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CITY 
MILK  SUPPLY 


BY 
HORATIO  NEWTON  PARKER 

FORMEBLY   HEALTH   OFFICER   OP   MONTCLAIR,    NEW   JERSEY,    LATELY 

INSTBUCTOR  IN   MUNICIPAL   AND  SANITARY   DAIRYING   AT 

THE   UNIVERSITY   OF  ILLINOIS.      MEMBER  OF  THE 

INTERNATIONAL   ASSOCIATION   OF    DAIRY 

AND   MILK   INSPECTORS. 


FIRST  EDITION 


McGRAW-HILL  BOOK  COMPANY,  INC, 

239  WEST  39TH  STREET.     NEW  YORK 


LONDON:  HILL  PUBLISHING  CO.,  LTD, 

6  &  8  BOUVERIE  ST.,  E.G. 

1917 


COPYRIGHT,  1917,  BY  THE 
McGRAW-HiLL  BOOK  COMPANY,  INC. 


THE    MAP1.K    3PHKSS     T  O  R  K. 


PREFACE 

The  writer's  experience  as  a  health  officer  and  as  a  teacher  has  led 
him  to  believe  that  there  is  need  for  a  book  telling  something  about  milk, 
how  it  is  produced  and  how  it  is  transported  and  delivered  to  city  milk 
consumers  and  of  the  methods  of  control  adopted  to  insure  its  purity. 
The  subject  is  a  broad  one  and  in  its  divisions  touches  several  specialized 
fields  which  are  the  domain  of  experts  so  that  necessarily  the  work  of 
these  men  has  been  drawn  on  for  material.  The  attempt  has  been  made 
to  give  them  due  credit  by  lists  of  sources  at  the  end  of  each  chapter. 

To  the  many  dairymen  and  city  milk  dealers  who  have  given  cordial 
welcome  to  their  farms  and  plants,  to  those  who  have  supplied  photo- 
graphs and  to  the  friends  who  have  helped  with  advice  in  the  prepara- 
tion of  the  manuscript  and  in  revision  of  the  proof  the  author  gives 
hearty  thanks. 
BOSTON,  MASSACHUSETTS, 
January,  1917. 


357953 


CONTENTS 

CHAPTER  I 

PAGE 

PREFACE.    .    .    .   ' v 

MILK 1 

Importance  of  the  Dairy  Industry — Consumption  of  Milk  in  the  United 
States — Milk  a  Valuable  Food — Definition  of  Milk — Breeding  of  the  Cow — 
Average  Chemical  Composition  of  Milk — Chemical  Composition  of  Skim- 
milk  and  Whey — The  Composition  of  Milk  in  Detail — Colostrum — Color  of 
Milk — Opacity  of  Milk — Specific  Gravity  of  Milk — Freezing  Point  of  Milk — 
Electric  Conductivity  of  Milk — Refractive  Index  of  Milk — Fat  Globules  in 
Milk — Cellular  Content  of  Milk — The  Enzymes  of  Milk — Water  in  Milk — 
Butterfat — Proteins — Casein — Lactalbumin — Lactglobulin  —  Carbohydrates 
— Lactose — Hexose  Sugar — Salts  in  Milk — Gases — Consumption  and  Flow 
of  Milk  Variable — Effect  of  Maltreating  Cows — Factors  Influencing  the 
Milk  Flow — Effect  of  Milking — Variation  in  Milk  from  Milking  to  Milking — 
Individuality  of  the  Cow  and  the  Production  of  Butterfat — Effect  of  the 
Condition  of  the  Cow  at  Calving — Changes  in  Character  of  Milk  during  the 
Lactation  Period — Seasonal  Variation  in  Composition — Breed  of  Cow  and 
Production  of  Butterfat — Bacteria  in  Milk — Classification  of  Bacteria  Found 
in  Milk — Importance  of  the  Various  Classes  of  Bacteria — Stages  in  the 
Bacterial  Decomposition  of  Milk — First  Stage — Second  Stage — Third  Stage — 
Fourth  Stage — Bacterial  Decomposition  of  Milk  Usually  Harmless — Dirty 
Milk — Infected  Milk — Grading  of  Milk — Modified  Milk — Milk  Beverages — 
Condensed  Milk  and  Milk  Powder. 

CHAPTER  II 

DISEASES  COMMUNICABLE  IN  MILK 28 

Milk  a  Vehicle  of  Infection — Discovery  ol  Disease  Germs — Classification 
of  Milk-borne  Diseases — Tuberculosis — Nature  of  Tuberculosis — Entrance 
of  Tuberculosis  Germs  into  the  Body— Passage  of  Tuberculosis  Germs  from 
the  Body — Infection  of  Milk  by  Germs  of  Tuberculosis  in  the  Feces — Fre- 
quency of  the  Infection  of  Milk  with  Tuberculosis — Length  of  Life  of 
Tuberculosis  Germs  Outside  the  Body — Mode  of  Infection  of  the  Herd — The 
Diagnosis  of  Tuberculosis — Physical  Examination — Tuberculin — Subcuta- 
neous Test — Tuberculin  Test  as  a  Criterion  for  Excluding  Milk  from  the 
Market— The  Intradermal  Test— The  Ophthalmic  Test— Value  of  the  Tuber- 
culin Test — Results  of  Tuberculin  Testing — Tuberculin  Testing  in  Wisconsin 
— Tuberculin  Testing  in  Hawaii — Tuberculin  Testing  in  North  Carolina — 
Tuberculin  Testing  in  Savannah,  Ga. — Tuberculin  Testing  in  Chester 
County,  Pennsylvania — Tuberculin  Testing  in  Minnesota— Tuberculin 
Testing  in  Montclair,  N.  J. — The  Lesson  of  Tuberculin  TJesting — Con- 
trol of  Tuberculosis  by  Immunization — Control  by  Tuberculin  Testing 
—The  Manchester  Method  of  Control — The  Ostertag  Method  of  Control 
—The  Bang  Method  of  Control — The  Birmingham  Method  of  Control — 
Use  of  the  Bang  Method  in  the  United  States — The  Disinfection  of  Stables — 
Tuberculosis  in  Swine — Viability  of  B.  Tuberculosis  in  Butter  and  Ice  Cream 

vii 


viii  CONTENTS 

PAGE 

—Viability  of  B.  Tuberculosis  in  Oleomargarine — Viability  of  Tuberculosis  in 
Cheese — Need  of  a  Comprehensive  Tuberculosis  Policy — Foot-and-mouth 
Disease — Anthrax — Cowpox — Rabies — Milk-sickness — Malta  Fever — Con- 
tagious Abortion — Sore  Teats — Gastro-enteritis  Caused  by  Udder  Infection — 
Gastro-enteritis  Caused  by  Fecal  Contamination — Unclean  Milk  at  the  U.  S. 
Naval  Academy — Diseases  of  Class  II — Typhoid  Fever — Effect  of  Lactic 
Acid  on  Disease  Germs — Possible  Infection  of  Butter  in  Wrapping — Para- 
typhoid Fever — Asiatic  Cholera — Diphtheria — Scarlet  Fever — Septic  Sore 
Throat — Study  of  Smith  and  Brown — Study  of  Krumwiede  and  Valentine — 
Studies  of  Smillie — Summary  of  Epidemics — Mode  of  Transmission  of  In- 
fectious Disease — Transmission  by  Milk — Infection  of  Milk  on  the  Farm — 
Infection  of  Milk  en  Route  to  the  Creamery  or  City — Infection  of  Milk  in  the 
City  Milk  Plant — Infection  of  Milk  by  Cans  and  Bottles — Infection  of  Milk  in 
Delivery — Infection  of  Milk  after  Delivery — Impossibility  of  Protecting  the 
Milk  from  Infection — Characteristics  of  Milk-borne  Epidemics — Injury  Done 
by  Milk-borne  Epidemics — Control  of  Milk-borne  Diseases. 

CHAPTER  III 

DAIKY  CATTLE  AND  THE  DAIRY   FARM 94 

Origin  of  Domesticated  Cattle — Introduction  of  Cattle  into  America — 
The  Dairy  Type — Holstein-Friesian — Ayrshire — Brown  Swiss — The  Chan- 
nel Islands  Cattle — Guernsey — Jersey — French-Canadian — Dual-purpose 
Cattle — Shorthorn — Choice  of  Breed — Importance  of  a  Purebred  Bull — Im- 
portance of  Testing  Cows — Cow-testing  Associations — Sheltering  Cattle — 
Types  of  Barns — Basement  Barns — Loft  Barns — Shed  Barns — Double 
Stabling  Barns — Combination  Barns — Round  Barns — Barn  Construction — 
Necessity  of  Good  Planning — Plan  of  Round  Barn — Plan  of  Rectangular 
Barn — Barn  Floor — Platforms — Alignment  of  the  Animals — Stall  Partitions 
— Gutters — Alleys — Walls — Stanchions — Mangers — Milk  Room — Office — • 
Dressing  Room — Ceiling — Lighting — Ventilation — Ventilation  by  Windows 
—The  King  System — Canadian  Experiments — Rutherford  System — Ven- 
tilation by  Pierced  Walls — Ventilation  by  Curtains— Watering  Cows — 
Care  of  the  Manure — Litter — Vermin  and  Flies — Mosquitos — Milk  Houses — 
Ice  Houses. 

CHAPTER  IV 

SANITARY  MILK  PRODUCTION.  .    .    .,  .  ;• .  _^'t  '..'>.  -'^^  -.    .    .."..  >   .    .  ..    .    .    ...   142 

Milk  Must  Satisfy  the  Purchaser — Dirty  Milk — Milk  of  Extra  Quality  More 
Expensive  to  Produce — Sources  of  Contamination — Bacteria  Derived  from 
the  Udder — Fecal  Contamination  of  Milk — Contamination  of  Milk  by  Dis- 
charges from  the  Nose  and  Mouth — Contamination  of  Milk  from  the  Coat 
of  the  Cow — Small-top  Milk  Pails — Milking  Machines — Contamination  of 
Milk  in  Straining — Influence  of  the  Cream  Separator  on  the  Bacterial  Count 
of  Cream  and  Skim-milk — Cooling  of  Milk — Aeration  of  Milk — Barn  Prac- 
tices in  Relation  to  Milk  Quality — Sterilizing  and  Protecting  the  Pails — Plas- 
tering— Painting  and  Whitewashing — Clipping  the  Cows'  Udders  and 
Flanks — Hand-  vs.  Machine-cleaning  of  Cows — Interpretation  of  the  New 
York  Station  Experiments — The  Open  Stable  and  the  Germ  Content  of 
Milk — Air-borne  Contamination — Contamination  from  Feeds — Contamina- 
tion from  Bedding — Contamination  from  Dairy  Utensils — The  Water 
Supply  of  the  Dairy  Farm — Contamination  of  Milk  by  Ice — Human  Con- 


CONTENTS  ix 

PAGE 

tamination  of  Milk — Contamination  of  Milk  by  Domestic  Animals  and 
Vermin — Contamination  of  Milk  by  Flies — Essentials  of  Clean  Milk  Pro- 
duction— The  North  System — Dairy  Farm  Score  Cards — Future  of  the  Score 
Card — Dirty  Dairies — Slop  Dairies — The  Cost  of  Milk  Production. 

CHAPTER  V 

THE  TRANSPORTATION  OF  MILK 193 

The  Hauling  of  Milk — Transportation  of  Milk  by  Steamboat — Trans- 
portation of  Milk  by  Electric  Cars — Transportation  of  Milk  by  Steam  Rail- 
roads— Philadelphia — Some  Economic  Features  of  Transportation  of  Milk  by 
Railroad — Temperature  of  Milk  in  Transit  by  Rail — Types  of  Cars  Used  in 
Transporting  Milk — Rates  of  Transporting  Milk — Improvement  in  Shipping 
Milk  in  Pittsburg — Temperatures  and  Age  of  Milk  Handled  by  Contractors 
— Use  of  Motor  Vehicles  in  Collecting  and  Delivering  Milk — Age  of  Milk 
When  Delivered  to  Consumers — Cost  of  Operating  Delivery  Wagons. 

CHAPTER  VI 

THE  MILK  CONTRACTOR ...    ...   228 

Advent  of  the  City  Milk  Problem — The  Milk  Contractor — Different 
Branches  of  Dairying  Dominate  Producing  Territory — Influence  of  Con- 
tractors in  Dairy  Districts — Basis  on  which  Milk  is  Purchased — Tendency  to 
Concentration — Methods  of  Paying  Producers — Milk  Plants — Country  Milk 
Plants— The  Item  of  the  Surplus— The  North  System— Handling  of  Milk 
in  Country  Plants — Cream — The  Cream  Separator — Advantages  of  City 
Milk  Plants — General  Features  of  City  Milk  Plants — Classification  of  City 
Milk  Plants — Basement  Plants — Ground  Floor  and  Basement  Plants — 
Single  Story  Plants — Plants  of  More  Than  One  Story — Minimum  Require- 
ments for  a  City  Milk  Plant — Environment  of  the  Milk  Plant — General 
Plan  of  the  Milk  Plant— Water  Supply  of  the  Milk  Plant— Plumbing  of 
the  Milk  Plant — Cost  and  Equipment  of  the  Milk  Plant — U.  S.  Depart- 
ment of  Agriculture  Milk  Plant  Score  Card — Medical  Inspection  of  the 
Employees — Platforms — Inspection  of  Plant — Age  of  Milk  on  Arrival  at 
Plant — Tasting  the  Milk — Drip  Pans — Wasjiing  of  Cans — Dirt  in  Milk — 
Clarification  of  Milk — Standardizing — Storage  in  Tanks — Preservation  of 
Food  by  Heat — Application  of  Pasteurization  to  Milk — The  Work  of 
Koplik — Work  of  Nathan  Straus — Pasteurization  Adopted  by  Milk  Contract- 
ors— Arguments  For  and  Against  Pasteurization — Pasteurization  Pre- 
vents the  -Spread  of  Contagion  by  Infected  Milk — Pasteurization  Lowers  the 
Infantile  Morbidity  Rate — Pasteurization  Checks  Bacterial  Changes  in 
Milk — Pasteurization  Delays  the  Souring  of  Milk— Uninspected  Milk 
Should  be  Pasteurized — Heating  Milk  Unnatural — Pasteurizing  Milk  and 
Dirty  Dairying — Spore-bearing  Organisms  Survive  Pasteurization — Other 
Bacteria  that  Survive  Pasteurization — Ability  of  B.  Coli  to  Survive  Pasteuri- 
zation— Ability  of  the  Streptococci  to  Survive  Pasteurization — Effect  of 
Pasteurization  on  Mould  Spores — Multiplication  of  Bacteria  in  Pasteurized 
Milk — Destruction  of  Toxins  by  Pasteurization — Physical  and  Chemical 
Changes  Induced  in  Milk  by  Pasteurizing — Suitability  of  Pasteurized 
Milk  for  Infant  Feeding — Milk  for  Babies  a  Special  Milk — Pasteurization 
an  Additional  Process — Milk  Liable  to  Recontamination  after  Pasteuriza- 
tion— Overconfidence  in  Pasteurized  Milk — Pasteurization  and  the  Score 
Card — Milk  Liable  to  Bovine  Infection — Impossible  to  Protect  Milk  from 


x  CONTENTS 

PAGE 

Human  Infection — Pasteurization  at  Low  Temperatures  Destroys  Disease 
Germs — Advent  of  the  Holder  Process — Success  of  Child  Welfare  Stations — 
Pasteurizing  Machines — Holders — Holders  of  the  Continuous  Type — Re- 
generative Pasteurizers — Bottling  Milk  Hot — Difficulties  Encountered  in 
Pasteurization — Importance  of  Temperature  Control — Actual  Pasteuriza- 
tion— Efficiency  of  Pasteurization — Method  of  Cooling — Inspection  of 
Pasteurizing  Plants — Sterilization  of  Milk  by  Electricity — Sterilization 
of  Milk  by  Ultra-violet  Rays — Cost  of  Pasteurization — Future  of  Pasteuri- 
zation— Use  of  Pasteurization  in  the  United  States — Cooling  Milk — 
Filling  the  Bottles— Bottle  Caps— Cost  of  Bottling  Milk— Bottle  Cases- 
Bottle  Caps — Milk  Bottles — Breakage  and  Misuse  of  Milk  Bottles — Paper 
Bottles — Bottle  Washing — Cost  of  Bottle  Washing — Storage  and  Inspec- 
tion of  Bottles — Sterilization  of  Bottles  by  Steam — Sterilization  of  Uten- 
sils, Etc.,  with  Washing  Powders — Sterilization  of  Bottles  with  Bleaching 
Powder — Milk  Cans — Item  of  Shrinkage  in  City  Milk  Plants — Homogenized 
Milk — Milk  Beverages — Recovery  and  Use  of  Casein — Care  of  Milk  Plant 
and  Creamery  Waste — Holding  Milk  at  Low  Temperature — Refrigeration 
in  the  Home — Economy  in  the  Use  of  Steam — Retail  Delivery  of  Milk — 
Collection — Country  Plant — Transportation  on  Railroads — City  Plant — 
Distribution — Family  Trade — Retail  Stores — Wholesale  Trade — Book- 
keeping— Retail  Price  of  Milk. 

CHAPTER  VII 

CONTROL  OF  THE  PUBLIC  MILK  SUPPLY ./ 370 

Early  Attempts  at  Control  in  Europe — Early  Attempts  at  Control  in  the 
United  States — Principles  of  Modern  Milk  Control — Federal  Control  of  the 
Milk  Supply — State  Control  of  the  Milk  Supply — Municipal  Control  of 
the  Milk  Supply — Control  of  the  Milk  Supply  by  the  Contractor — Milk 
Codes— The  Grading  of  Milk— The  Milk  Code  Should  be  Suited  to  the 
Community — Type  of  Ordinance  Proposed  by  Whitaker — Type  of  Ordinance 
Proposed  by  the  New  York  Milk  Committee — Standard  Rules  for  the  Pro- 
duction, Handling,  and  Distribution  of  Milk — Production  of  Raw  Milk — 
Subnormal  Milk — Production  of  Cream — Production  of  Pasteurized  Milk — 
Milk  for  Pasteurization — Production  of  Pasteurized  Cream — Production 
of  Certified  Milk — Hygiene  of  the  Dairy — Transportation — Veterinary  Super- 
vision of  the  Herd — Bacteriological  Standards — Chemical  Standards  and 
Methods — Methods  and  Regulations  for  the  Medical  Examination  of 
Employees.  Their  Health  and  Personal  Hygiene — Enforcement  of  the 
Milk  Code — The  Milk  Supply  of  a  City  a  Valuable  Asset — Personnel  of  the 
Milk  Inspection  Bureau — Necessity  of  Defining  the  General  Policies 
Adopted — Necessity  of  a  General  Survey  of  the  Producing  Territory — Office 
Records — Important  Phases  of  Milk  Control — Dairy  Farm  Inspection — 
Inspection  of  Milk  in  Transit — Milk  Plant  Inspection — Oversight  of  the  De- 
livery System — Sale  of  Milk  in  Stores — Milk  in  the  Home — Laboratory 
Tests — Sediment  Test — Lactometer  Test — Chemical  Tests — Tests  for  Pre- 
servatives— Biological  Tests — Determination  of  the  Cellular  Content^- 
Biological  Test  for  Heated  Milk — The  Bacteria  Count — Methods  of  Making 
the  Bacterial  Count — Accuracy  of  Bacterial  Counts — Some  Factors  That 
Should  be  Considered  in  Using  the  Bacterial  Count — Significance  of  Pre- 
dominance of  Acid-forming  and  of  Putrefactive  Bacteria — Significance  of 
the  Streptococci — Significance  of  the  B.  Coli — Significance  of  the  B.  welchii — 


CONTENTS  xi 

PAGE 

Bacterial  Tests  of  Pasteurized  Milk — Prevention  of  Milk-borne  Epidemics — 
Methods  of  Maintaining  Public  Interest  in  the  Milk  Supply — Measure  of 
Success  in  Controlling  the  Milk  Supply — Infant  Mortality  and  the  Milk 
Supply — Bottles  of  the  Thermos  Type — Child  Welfare  Stations — Milk  Sup- 
plies of  Large  and  Small  Cities  Contrasted — Cream — Daily  Consumption 
of  Milk  in  the  Larger  Cities  of  the  United  States — Annual  Reports — The 
Public  Milk  Supply. 

INDEX.  .487 


CITY  MILK  SUPPLY 

The  milk  business  is  not  the  farmer's  business,  nor  the  contractor's,  nor  yet  the 

consumer's;  it  is  the  community's  business,  and  unless  the  members  of  the 

community  work  together  for  good  milk,  they  will  never  get  it. 


CHAPTER  I 
MILK 

The  city  milk  business  of  the  United  States  is  a  development  of  the  past 
75  years.  Prior  to  1840  very  little  milk  was  shipped  by  rail;  practically 
all  of  it  was  brought  by  wagons  from  farms  in  the  surrounding  country 
or  was  produced  within  city  limits.  At  that  time  no  city  in  the  country 
had  a  population  of  half  a  million.  Boston  had  about  100,000  inhabi- 
tants and  New  York  City  about  300,000.  However,  the  largest  cities 
were  beginning  to  find  the  local  sources  of  milk  supply  inadequate  and 
were  reaching  out  for  country  milk.  By  1843  many  farmers  within  50 
miles  of  Boston  were  shipping  milk  regularly  by  rail  to  the  city  and  soon 
other  cities  got  increasingly  large  amounts  of  milk  in  the  same  way.  The 
business  was  a  new  one  and  naturally  those  who  were  engaged  in  it  han- 
dled it  in  a  crude  way.  Abuses  crept  in  and  became  so  flagrant  that  about 
1860  the  first  attempts  were  made  to  regulate  it,  by  discouraging  the 
practices  of  skimming  and  watering.  Apparently  they  were  only  partially 
successful.  Meanwhile  the  milk  business  .grew  to  importance  without 
exciting  more  than  a  grumbling  interest  on  the  part  of  the  public.  How- 
ever, it  was  about  to  enter  a  new  era.  In  the  period  from  1885  to  1890 
the  regular  collection  of  milk  samples  became  common  and  the  acceptance 
of  the  germ  theory  of  disease  led  to  the  tracing  of  certain  outbreaks  of  con- 
tagion to  milk  supplies.  Soon,  the  medical  profession,  milk  producers 
and  the  public  recognized  that  the  milk  business  must  be  reformed  and 
put  on  a  basis  which  would  make  the  products  above  reproach.  Regula- 
tion was  undertaken  with  assurance  and  in  a  cavalier  spirit  but  after  many 
disappointments  and  bitter  controversies  it  was  gradually  perceived 
,that  all  concerned  had  much  to  learn  before  the  problem  of  delivering 
immense  quantities  of  good  safe  milk  could  be  solved.  Investigations 
of  different  phases  of  the  question  were  made  by  physicians,  bacteri- 
ologists, chemists,  health  officers,  economists,  engineers,  railroad  men, 
dairymen,  lawyers  and  others.  Manufacturers  of  dairy  machinery  so  im- 
proved the  devices  used  as  to  make  the  handling  of  milk  cleaner  and  safer. 

1 


„*«  •*» « 


CITY  MILK  SUPPLY 


The  result  of  all  these  forces  is  that  in  the  last  25  years,  there  has  emerged 
a  new  art,  city  milk  supply,  still  far  from  perfect  but  which  is  advancing 
steadily. 

Importance  of  the  Dairy  Industry. — Progress  is  being  made  along 
several  different  lines.  Chemists  are  studying  the  composition  of  milk 
and  the  changes  it  undergoes  in  being  made  into  various  sorts  of  dairy 
products.  Farmers  are  improving  their  herds  and  introducing  more 
sanitary  and  economical  methods  of  dairying.  Railroads  are  solving 
the  problems  that  arise  in  transporting  milk  and  contractors,  those  that 
attend  the  gathering  and  distributing  of  enormous  quantities  of  milk. 
Health  officers  are  working  out  rational  methods  of  milk  control  and  the 
general  public  through  various  organizations  of  citizens,  in  whatever  way 
it  can,  is  helping  to  develop  this  important  business. 

It  is  estimated  that  in  1914  there  were  20,737,000  dairy  cows  in  the 
United  States  and  that  their  total  value  was  $1,118,487,000.  The  whole 
quantity  of  milk  used  raw  on  farms,  raw  in  villages,  as  market  milk  in 
cities,  in  condenseries,  for  the  manufacture  of  butter  and  cheese  on  the 
farm  and  in  butter  and  cheese  factories,  is  estimated  at  9  billion  gallons 
or  77.4  billion  pounds  per  annum,  to  which  should  be  added  the  milk  used 
for  feeding  calves  and  other  stock  and  that  used  in  small  quantities  for 
other  purposes.  Of  this  milk,  the  market  milk  consumed  in  cities  of 
over  2,500  inhabitants  is  1  billion  gallons  or  8.6  billion  pounds  and,  assum- 
ing the  consumption  per  capita  to  be  the  same  in  villages  of  less  than  2,500, 
the  total  use  of  milk  therein  amounts  to  600,000  million  gallons  or  5.16 
billion  pounds. 

Consumption  of  Milk  in  the  United  States. — The  consumption  of 
market  milk  in  cities  of  the  United  States  is  often  taken  at  0.6  pt.  per 
capita  but  this  is  a  crude  figure  and  is  usually  arrived  at  by  dividing  the 
total  amount  of  milk  distributed  daily  by  the  total  population.  The 
truth  is,  the  wealthy  and  well-to-do  get  more  milk  than  the  poorer  people 
so  that  the  amount  of  milk  used  by  the  average  citizen  is  considerably 
less  than  0.6  pt.  In  order  to  get  information  concerning  the  use  of  milk 
in  the  home,  Williams  made  a  careful  study  of  15  sections  of  Rochester, 
N.  Y.  Each  section  differed  from  the  others,  in  wealth,  social  position 
or  nationality  and  all  together  they  embraced  over  5,000  or  about  one- 
tenth  of  the  homes  of  the  city.  The  result  of  the  study  is  given  in  Table 
1.  It  shows  that  the  population  of  children  under  5  years  of  age  was 
greater  among  the  poor  than  among  the  well-to-do.  The  consumption  of 
milk  by  21,600  people  was  5,278  qt.  of  milk  per  day  or  at  the  rate  of  but 
little  more  than  0.24  pt.  per  capita.  The  poor  not  only  used  less  milk 
and  bought  it  in  smaller  quantities  than  the  well-to-do  but  the  use  of 
store  milk  and  of  condensed  milk  was  largely  confined  to  the  laboring 
classes. 


MILK 


TABLE  1. — CONSUMPTION  OF  MILK  IN  15  REPRESENTATIVE  SECTIONS  OF  ROCHESTER, 

N.  Y.   (WILLIAMS) 


Families  using  daily  — 

Families  using  — 

Class 

Num- 
ber of 
homes 

Num- 
ber of 
people 

Chil- 
dren 
under 
5 

Amount 
milk 
used 
daily 

H 

1 

IV* 

2 

2V* 

3 

Certi- 

Condensed 
milk 

Store 

years 

(quarts) 

qt. 

qt. 

qt. 

qt. 

qt. 

qt. 

millr 

milk 

miiK 

Exclu- 
sively 

Partly 

Chiefly  colored.  .  . 

231 

1,128 

67 

245 

51 

122 

10 

24 

11 

6 

11 

4 

48 

American  laboring 

523 

2,308 

159 

532 

131 

242 

21 

67 

50 

18 

23 

30 

70 

American  laboring 

462 

2,067 

143 

475 

135 

204 

28 

53 

1 

16 

2 

21 

37 

103 

Well-to-do  

283 

1,176 

67 

398 

35 

132 

27 

61 

1 

26 

14 

1 

10 

4 

German-American 

laboring           .  .  . 

527 

2,647 

234 

626 

117 

231 

41 

80 

36 

39 

2 

Well-to-do  

115 

518 

19 

169 

12 

57 

9 

24 

1 

11 

5 

Italian  laboring.  .  . 

643 

3,172 

538 

388 

218 

143 

26 

26 

1 

8 

18 

52 

25 

29 

Jewish  laboring.  .  . 

477 

2,316 

310 

623 

65 

170 

63 

103 

4 

26 

11 

16 

32 

28 

German  laboring.. 

234 

1,245 

94 

289 

37 

90 

33 

39 

1 

16 

10 

5 

American  middle.  . 

450 

1,939 

112 

523 

92 

27 

39 

66 

21 

8 

4 

13 

Well-to-do  

201 

891 

24 

352 

17 

63 

12 

66 

. 

32 

18 

1 

Well-to-do  

99 

495    1      20 

190 

5 

24 

8    24 

25 

4 

I 

Well-to-do  

209 

845         41 

303 

23 

88 

56 

20 

29 

American  laboring 

191 

851 

57 

165 

72 

59 

12 

19 

5 

18 

11 

10 

American  laboring 

786 

200 

1,100 

192 

258 

44 

38 

36 

2 

39 

62 

Milk  a  Valuable  Food.— The  milk  industry  has  attained  this  im- 
portance because  milk,  skim-milk,  butter  and  cheese  are  among  the  best 
and  cheapest  of  foods.  Most  people  are  fond  of  them  and  digest  them 
easily.  Good  fresh  milk  is  all  but  essential  to  the  welfare  of  young  chil- 
dren, and  to  the  nursling  that  for  any  reason  is  deprived  of  its  mother's 
milk,  cow's  milk  is  practically  indispensable.  The  reason  that  milk  is 
such  good  food  must  be  sought  in  its  composition. 

Definition  of  Milk. — Milk  is  the  nutritive  secretion  of  the  mammary 
glands.  In  a  general  way  all  milks  are  similar  for  they  are  watery  fluids 
containing  fats,  proteins,  sugars,  salts  and  gases.  The  fat  is  in  suspension, 
the  proteins  are  mostly  in  colloidal  suspension  but  in  part  in  true  solution 
and  the  salts  likewise  are  in  solution  and  suspension,  whereas  the  sugars 
and  gases  are  in  true  solution.  Each  species  of  animal  has  its  own 
peculiar  milk;  that  of  animals  of  the  same  species  differs  a  little  and  the 
milk  of  a  single  animal  is  of  slightly  inconstant  quality.  Since  in  the 
United  States  the  milk  of  the  cow  is  the  only  one  that  is  of  commercial  im- 
portance, it  is  the  one  with  which  this  book  deals. 

Breeding  of  the  Cow. — Under  the  best  management  a  heifer  is  bred 
at  15  to  18  months  of  age,  the  period  of  sexual  maturity,  being  reached 
earlier  by  some  breeds  than  others.  After  a  period  of  gestation  of  9 
months  she  calves  and  comes  into  milk.  At  an  estrum  occurring  about 
3  months  later,  she  is  bred  again,  but  continues  to  furnish  milk  for  about 
10  months  when  the  nutrients  that  have  been  devoted  to  milk  produc- 


CITY  MILK  SUPPLY 


tion  are  needed  for  nourishment  of  the  fetus  so  that  the  flow  falls  off  and 
usually  dries  up.  The  udder  then  enters  a  resting  stage,  and  the 
animal  goes  through  a  period  of  recuperation,  or  conditioning  for  6  weeks 
or  more,  when  she  drops  another  calf  and  enters  a  second  lactation 
period.  If  this  rest  is  not  given  the  cow  she  begins  the  new  lactation 
period  at  a  low  level  of  production.  Animals  that  remain  farrow  usually 
give  milk  for  about  2  years,  though  some  farrow  cows  continue  in  milk 
for  a  long  time. 

Average  Chemical  Composition  of  Milk. — The  average  chemical 
composition  of  milk  is  indicated  in  Table  2  which  is  made  up  from  analyses 
from  several  sources,  but  in  reality  it  is  impossible  to  state  the  average 
composition  exactly  for  the  milk  of  every  dairy  district  is  determined  by 
the  dominant  breed  of  cow;  thus  in  a  Holstein  the  average  would  differ 
from  that  of  a  Guernsey  section  and  that  again  from  one  where  the  cows 
were  mostly  natives. 

TABLE  2. — AVERAGE  COMPOSITION  OF  Cow's  MILK 


Number  and  source  of  analyses 

Water 

Fat 

Milk 
sugar 

Casein 

Albumin 

Ash 

Other  con- 
stituents 

280,000   analyses   Aylesbury 

Dairy  England 

87  35 

3  74 

4  70 

3   00 

0   40 

0  75 

0   06 

5,220  American  analyses  com- 

piled by  Van  Slyke  

87.10 

3.90 

5.10 

2.50 

.0.70 

0.70 

Average  cheese-factory  milk, 

New   York   State,    May  to 

November  

87.40 

3.75 

5.00 

2.45 

0.70 

0.70 

The  composition  of  milk  varies.  As  a  rule,  the  percentage  of  milk 
sugar  and  ash  are  most  constant  and  that  of  the  fat  is  most  variable  while 
the  protein  varies  with  the  fat  but  to  a  smaller  extent.  According  to 
Van  Slyke  the  butterfat  in  the  milk  of  an  individual  cow  varies  from  less 
than  2  to  over  10  per  cent.,  the  casein  from  2  to  4  per  cent.,  the  albumin 
from  0.5  to  0.9  per  cent.,  the  casein  and  albumin  together  from  2.5  to  6 
per  cent.,  the  lactose  from  4  to  6  per  cent.,  and  the  salts  from  0.7  to  0.9 
per  cent.  These  variations  in  the  constituents  of  milk  may  be  regarded 
as  usual:  butterfat  3  to  6  per  cent.,  solids-not-fat  8.5  to  9  per  cent.,  pro- 
teins 3  to  5  per  cent.,  milk  sugar  4  to  6.5  per  cent,  and  ash  0.7  to  0.8 
per  cent.  The  milk  that  reaches  the  consumer  is  usually  the  mixed  prod- 
uct of  several  cows  so  that  variations  in  the  milk  of  the  individual  cows 
counterbalance  one  another  with  the  result  that  considerable  fluctuations 
rarely  occur. 

Commonly  an  analysis  of  milk  includes  only  a  determination  of  the 
specific  gravity,  the  butterfat  and  total  solids;  more  complete  analyses 
give  the  milk  sugar,  casein,  albumin,  ash  and  index  of  refraction.  The 


MILK 


analytical  statements  of  the  composition  of  milk  by  three  prominent 
analysts  are  as  follows: 


TABLE  3 


Water 

Fat 

Milk 
sugar 

Casein 

Albumin 

Ash 

Solids- 
not-fat 

T.S. 

Van  Slyke 

87   1 

3  9 

5  10 

2  5 

0   7 

0  70 

9   0 

12  9 

=  100 

Babcock  
Blythe 

87.3 
87  2 

3.6 
3  9 

4.50 
4  75 

3.0 
3  0 

0.8 
0  4 

0.70 
0  75 

9.1 

8  9 

12.7 
12  8 

=  100 
-100 

Chemical  Composition  of  Skim-milk  and  Whey. — Van  Slyke  gives 
the  percentage  composition  of  milk  skimmed  with  a  separator  as: 
water  90.30,  total  solids  9.70,  butterfat  0.10,  casein  2.75,  albumin  0.80, 
sugar  5.25  and  ash  0.80.  His  percentages  for  whey  are:  water  93.40, 
total  solids  6.60,  butterfat  0.35,  casein  0.10,  albumin  0.75,  sugar  4.80  and 
ash  0.60. 

The  Composition  of  Milk  in  Detail. — From  the  average  composi- 
tion of  milk  it  is  well  to  pass  to  a  consideration  of  its  principal  compo- 
nents and  the  extent  to  which  they  may  be  expected  to  vary. 

Colostrum. — The  secretion  of  milk  is  preceded  by  that  of  colostrum. 
For  a  little  while  before  and  a  short  time  after  parturition  the  udder 
yields  this  fluid  which  is  small  in  amount,  viscous,  of  a  yellow  color,  a 
slimy  appearance  and  a  pungent  taste.  Its  specific  gravity  varies  from 
1.046  to  1.079  and  its  composition,  according  to  Engling  is  that  given  in 
Table  4. 

TABLE  4. — THE  PERCENTAGE  COMPOSITION  OF  COLOSTRUM  (ENGLING) 

Average 

Water. . . 76.60-67.43  71.69 

Fat ,'.  .    1.88-  4.68  3.37 

Casein 2.64-  7.14  4.83 

Albumin 11.18-20.21  15.85 

Sugar 1.34-  3.83  2.46 

Ash..                                  1.18-  1.23  1.78 

The  function  of  the  colostrum  is  not  known.  Some  are  of  the  opinion 
that  it  furnishes  nourishment  to  the  newborn  calf,  not  so  dissimilar  from 
that  it  received  through  the  placenta  as  to  make  the  change  in  food  violent. 
Others  surmise  that  colostrum  starts  up  digestion  in  the  calf  and  that  it 
has  laxative  properties  that  serve  to  rid  the  digestive  system  of  meconium. 

The  change  from  the  secretion  of  colostrum  to  that  of  milk  is  gradual 
and  the  time  it  takes  to  make  it  varies  with  different  animals.  The 
nature  of  the  changes  is  indicated  in  Table  5.  Usually  4  days  after 
calving  the  milk  may  be  sold  as  market  milk,  or  be  made  into  butter 
and  cheese,  but  it  often  is  2  or  3  weeks  before  the  milk  is  entirely  normal. 


6  CITY  MILK  SUPPLY 

The  ordinances  of  boards  of  health  prohibit  the  use  of  colostrum  by  for- 
bidding the  sale  of  milk  for  a  considerable  period  before  and  after  calving. 


TABLE  5. — CHANGE  OF  COLOSTRUM  TO  NORMAL  MILK   (HOUDET) 


Date 

Fat,  per 
cent. 

Sugar, 
per  cent. 

Soluble 
proteins, 
per  cent. 

Colloidal 
proteins, 
per  cent. 

Calcium 
phosphate, 
per  cent. 

Other 
salts, 
per  cent. 

Right  after  calving  

5  69 

3   30 

0  51 

14   05 

0  51 

0  54 

1  day  after  calving 

4  48 

4  05 

0  93 

5  21 

0  43 

0  43 

2  days  after  calving  .'•„. 

5.70 

4  32 

1  98 

3  52 

0  43 

0  45 

3  days  after  calving  
4  days  after  calving  •  . 
6  days  after  calving  ......... 
8  days  after  calving 

7.40 
3.20 
4.20 
4  10 

4.26 
4.44 
4.64 
4  96 

2.41 
0.56 
1.19 

0  48 

3.45 
5.20 
4.02 
3  56 

0.43 
0.40 
0.38 
0  40 

0.40 
0.30 
0.29 
0  30 

14  days  after  calving  

3.85 

5.03 

0.58 

3.74 

0.35 

0.36 

Color  of  Milk. — Milk  is  a  yellowish-white  opaque  fluid  having  a 
slightly  acid  reaction  to  phenolphthalein  and  an  amphoteric  reaction  to 
litmus;  it  is  of  sweet  taste  and  of  indefinable  characteristic  odor.  The 
yellow  color  is  derived  from  the  fat  globules  and  varies  greatly  in  the 
milk  of  different  breeds  and  also  in  the  milk  of  the  same  cow  at  different 
seasons,  generally  being  paler  during  the  winter  months  and  of  greater 
intensity  soon  after  the  cow  is  put  on  pasture.  By  feeding  experiments 
Palmer  and  Eckles  proved  that  milk  owes  its  color  principally  to  carotin 
but  also  to  xanthophylls.  These  pigments  are  not  built  up  in  the  cow's 
body  but  are  merely  taken  up  in  the  food  and  subsequently  secreted  in 
the  butterfat.  In  thin  films,  especially  after  skimming,  milk  has  a 
bluish  tinge  but  the  blueness  is  not  true  color  being  rather  in  the  nature  of 
opalescence  caused  by  tiny  particles  of  phosphate  of  lime  that  remain 
undissolved  in  the  milk  plasma. 

Opacity  of  Milk. — The  opacity  of  milk  is  due  to  the  casein  interfering 
with  the  passage  of  light  through  the  fluid. 

Specific  Gravity  of  Milk. — The  specific  gravity  of  the  milk  of  indi- 
vidual cows,  at  60°F.  varies  from  1.0135  to  1.0397  but  in  the  mixed 
milk  of  a  herd,  rarely  falls  outside  the  limits  1.0130  to  1.034.  Since 
butterfat  is  lighter  than  water,  its  increase  lowers  the  specific  gravity 
whereas  an  increase  in  the  solids-not-fat,  raises  it.  Hence  skimming 
milk  increases  its  specific  gravity  and  watering  lowers  it.  Consequently, 
taking  the  specific  gravity  is  widely  practised  to  detect  this  sort  of  tamper- 
ing. As  the  milk  may  be  manipulated  to  pass  the  test  it  serves  merely 
as  an  indication.  The  test  is  usually  made  with  a  lactometer,  of  which 
there  are  two  kinds,  the  Quevenne  and  the  New  York  Board  of  Health, 
in  common  use  in  the  United  States.  The  latter  is  used  less  generally 
than  the  former. 


MILK  7 

Freezing  Point  of  Milk. — Milk  freezes  at  31°F.  As  a  can  of  milk 
freezes,  the  solids,  except  fat,  are  excluded  from  the  ice  so  that  the  portion 
that  remains  unfrozen  contains  more  casein,  milk  sugar  and  ash  than 
the  frozen,  while  the  latter  carries  more  fat  because  it  rises  to  the  top 
and  is  entangled  by  the  ice  in  freezing.  So  samples  taken  for  analysis 
from  partly  frozen  cans  do  not  represent  the  true  composition  of  the  milk. 

Electric  Conductivity  of  Milk. — Because  of  the  dissolved  salts  that 
it  contains,  milk  passes  the  electric  current,  the  electric  conductivity 
being  dependent  on  the  degree  of  dissociation  of  the  salts  which  it  carries. 
The  resisting  power  of  milk  varies  between  180  and  210  ohms. 

Refractive  Index  of  Milk. — The  refractive  index  of  milk  varies  with 
the  composition;  in  normal  milk  the  refractive  index  ranges  from  1.3470 
to  1.3515.  A  minimum  of  1.3435  is  rarely  observed. 

Fat  Globules  in  Milk. — Under  the  microscope  the  most  conspicuous 
elements  of  milk  are  the  fat  globules.  They  have  a  pearly  luster  and 
vary  in  size  from  0.001  to  0.01  mm.  in  diameter  averaging  about  0.005 
mm.  and  become  smaller  and  smaller  from  the  first  milk  to  the  strippings. 

As  the  period  of  lactation  advances,  the  number  of  large  globules 
decreases  and  of  small  ones  increases.  Apparently  the  age  of  the  cow 
has  no  relation  to  the  size  of  the  globules.  Breed  affects  the  size  of  the 
globules,  the  Holsteins  and  Ayrshires  giving  small,  the  Brown  Swiss 
medium  and  the  Shorthorn,  Guernsey  and  Jersey  large  ones,  but  in  this 
matter  individual  cows  differ  markedly.  The  fat  globules  are  arranged 
in  groups  or  clumps  in  the  milk  instead  of  being  distributed  uniformly 
throughout  it,  a  matter  of  practical  importance,  for  when  these  clumps 
are  broken  up,  either  by  heating  or  centrifugalizing  the  milk,  it  does  not 
cream  well. 

Cellular  Content  of  Milk. — Stained  milk  smears  under  high  powers 
of  the  microscope  reveal  numerous  cells  that  have  caused  much  discus- 
sion. They  are  now  considered  to  be:  (1)  epithelial  cells  from  the  milk 
ducts  and  milk  cistern;  (2)  mononuclear  and  polynuclear  cells;  and  (3)  red 
blood  cells.  At  one  time  large  numbers  of  these  cells  were  believed  to 
indicate  inflammatory  conditions  in  the  udder  and  it  was  proposed  to 
exclude  from  the  market,  milk  that  showed  more  than  a  certain  number 
of  cells  per  microscopic  field,  but  it  is  now  recognized  that  perfectly 
healthy  animals  at  times  shed  epithelial  cells  in  large  numbers  and  the 
proposal  is  regarded  as  untenable.  The  presence  of  large  numbers  of 
polymorphonuclear  cells  together  with  long-chained  streptococci  is 
strongly  indicative  of  mammitis  and  warrants  an  investigation  of  the 
herd  or  cow  supplying  the  milk. 

The  Enzymes  of  Milk. — Besides  the  constituents  already  mentioned 
milk  contains  certain  enzymes  or  soluble  ferments  derived  from  living 
cells.  The  most  important  of  them  are  galactase,  lipase,  lactokinase, 
catalase,  peroxidase  and  reductase.  The  origin  of  the  ferments  is  not 


8  CITY  MILK  SUPPLY 

known;  some  believe  that  they  are  secreted  from  the  mammary  gland 
while  others  suggest  that  they  may  be  derived  from  the  bacteria  of  the 
udder. 

The  enzymes  are  destroyed  by  heat;  most  of  them  withstand  140°  to 
149°F.  for  some  time  without  material  injury;  most  have  their  activity 
weakened  between  149°  and  158°F.  and  all  of  them  are  destroyed  on 
relatively  short  exposures  to  temperatures  between  158°  and  176°F. 

The  function  of  the  enzymes  in  milk  is  not  known.  It  is  the  theory 
of  some  physicians  that  they  assist  in  digesting  milk,  and  they  attribute 
the  supposed  difficulty  of  digestion  of  boiled  as  compared  with  raw  milk 
to  the  destruction  of  enzymes  by  heat;  so  partly  for  this  reason  much 
attention  has  been  paid  to  the  temperature  at  which  the  pasteurization 
of  milk  is  conducted. 

With  regard  to  the  several  chemical  constituents  of  milk,  certain 
facts  are  important. 

Water  in  Milk. — Of  them  all,  water  is  present  in  the  largest  propor- 
tion, for  it  makes  up  about  87  per  cent,  of  the  milk. 

Butterfat. — Butterfat  is  present  in  milk  in  the  form  of  transparent 
globules  of  which  it  has  been  estimated  there  are  100  million  in  a  single 
drop.  In  freshly  drawn  milk  the  globules  are  suspended  in  the  serum 
but  on  setting  the  milk  they  gradually  rise  to  the  surface  and  form  cream. 

Butterfat  is  not  a  single  chemical  compound  but  a  mixture  of  several 
ethereal  salts  of  glycerol  called  glycerides.  It  is  not  known  how  the 
fatty  acids  are  combined  but  probably  three  acid  radicals  are  united 
with  each  glycerol  residue,  thus: 

(  C4H702 

CaEU  |  Ci8H3302     Glyceryl  butyro-oleo-stearate. 
I  CisHssC^ 

For  convenience  the  composition  of  butterfat  is  often  stated  as  though 
each  glyceride  existed  separately;  that  is  as  though  the  butterfat  contained 
so  much  butyrin,  caproin,  etc.  There  are  about  10  of  these  glycerides 
and  butterfat  contains  about  12.5  per  cent,  of  glycerides  in  combination 
with  acids  which  are  divided  into  two  groups. 

Group  1. — Non-volatile  and  insoluble  in  water:  palmitic,  oleic, 
myristic,  stearic  and  lauric. 

Group  2. — Volatile  and  soluble  in  water:  butyric  and  caproic. 

Butterfat  on  an  average  contains  about  40  per  cent,  of  palmytin, 
34  per  cent,  of  olein,  10  per  cent,  of  myristin,  6  per  cent,  of  butyrin  and 
from  1  to  3  per  cent,  of  other  glycerides.  The  glycerides  composing 
butterfat  have  different  melting  points;  consequently  the  melting  point 
of  butterfat  varies  with  the  proportion  of  the  several  glycerides  present 
and  ranges  from  85.1°  to  91.4°F.  The  character  of  butterfat,  also,  is 
determined  by  the  proportions  in  which  the  glycerides  exist.  Palmytin 


MILK  9 

and  myristin  make  butterfat  harder  while  olein  and  butyrin  make  it 
softer. 

The  churning  temperature  is  largely  determined  by  the  relative 
amounts  of  hard  and  soft  fats;  other  conditions  being  the  same,  the  harder 
the  fat  the  higher  the  churning  temperature.  The  relative  amounts  of 
hard  and  soft  fats  are  influenced  by:  (1)  the  breed,  (2)  the  feed,  (3)  the 
period  of  lactation,  and  (4)  the  individuality  of  the  cow.  The  butterfat 
of  Jerseys  is  harder  than  that  of  the  Holsteins  and  therefore  requires 
a  higher  temperature — about  6°F. — to  churn.  It  is  inherent  in  some  cows 
to  produce  a  soft  and  in  others  a  hard  butterfat.  With  the  advance  of 
the  lactation  period,  the  proportion  of  hard  fat  increases  and  churning 
becomes  difficult.  By  feeding  certain  fats  the  character  of  butterfat 
may  be  affected. 

The  soluble  fats,  of  which  butyrin  is  the  most  important,  help  to 
impart  to  milk  and  cream  their  characteristic  flavor.  Butyrin  is  found 
only  in  butterfat  and  so  distinguishes  it  from  vegetable  and  all  other 
animal  fats. 

Recent  investigations  at  the  University  of  Wisconsin  Agricultural 
Experiment  Station  have  demonstrated  that  there  is  an  unknown  sub- 
stance in  butterfat,  in  the  fat  of  eggs  and  in  the  fat  of  certain  organs 
like  the  kidneys  which  is  essential  to  young  animals  to  make  normal 
growth,  but  which,  as  far  as  known,  does  not  exist  in  plants  or  in  body  fat 
in  quantities  large  enough  to  satisfy  them.  This  means  that  all  fats 
are  not  equally  valuable  to  animals  during  growth  and  in  the  opinion  of 
McCollum,  indicates  that  oleomargarine,  since  it  contains  a  consider- 
able admixture  of  the  body  fat  of  animals,  is  not  equal  in  physiological 
properties  to  an  equal  amount  of  butter,  although  it  may  possess  as 
much  energy  and  equal  digestibility. 

Proteins. — Casein. — Casein  is  the  most  important  protein  of  milk 
because  it  constitutes  about  80  per  cent,  of  all  the  proteins  and  because 
its  presence  makes  the  manufacture  of  cheese  and  other  products  pos- 
sible. It  is  held  in  colloidal  suspension  in  the  milk  serum  and  is  not  pre- 
cipitated therefrom  by  boiling.  Pure  casein  is  white  and  amorphous 
and  without  taste  or  smell.  Richmond  considers  it  probable  that  casein 
exists  in  milk  as  a  calcium  sodium  salt  combined  with  one  molecular 
proportion  of  tricalcium  phosphate.  In  the  souring  of  milk  the  lactic 
acid  combines  with  the  calcium  of  this  compound  forming  free  casein 
which  on  the  formation  of  more  acid  takes  up  the  acid  without  definite 
chemical  combination  to  make  the  curd  of  sour  milk.  Similar  changes 
occur  when  milk  is  treated  with  other  acids,  such  as  acetic,  hydrochloric 
or  sulphuric.  In  this  way  casein  is  precipitated  from  skim-milk  to  be 
manufactured  into  size,  paints,  combs  and  other  things.  Casein  is 
also  precipitated  in  the  slime  of  separator  and  of  clarifier  bowls.  Dilute 
solutions  of  the  alkalies,  such  as  caustic  soda  and  ammonia,  act  upon 


10  CITY  MILK  SUPPLY 

casein  and  its  salts  with  acids,  forming  compounds  that  dissolve  easily 
in  water.  Some  of  them  are  marketed  as  foods  and  patent  medicines, 
such  as  Plasmon,  Nutrose,  Sanatogen,  Eucasein,  Galactogen,  etc.  One 
of  the  most  characteristic  properties  of  milk  is  the  coagulation  by  the 
enzyme  contained  in  rennet.  It  is  this  that  makes  cheese  manufacture 
possible.  The  curd  formed  by  the  action  of  rennet  is  called  calcium 
paracasein. 

Lactalbumin. — Lactalbumin  makes  up  15  per  cent,  or  more  of  the 
milk  protein.  It  is  held  in  solution  in  the  milk  serum  but  is  partially 
precipitated  therefrom  by  heating  to  158°F.  Lactalbumin  is  not  acted 
on  by  rennet  nor  is  it  coagulated  by  acids  at  ordinary  temperatures. 

Lactglobulin. — Lactglobulin  is  in  solution  in  the  milk  serum  but 
exists  only  in  traces.  It  is  coagulated  by  heat  at  161. 6°F.  but  not  by 
rennet  or  acids. 

Carbohydrates. — Lactose. — The  principal  carbohydrate  of  milk  is 
the  sugar,  lactose.  It  is  the  specific  product  of  the  mammary  gland 
and  is  found  only  in  milk.  It  has  the  symbol  Ci2H22Oii-H2O  and  is 
readily  converted  by  bacteria  into  lactic  acid, 

H     OH 

H— C— C— COOH. 

I 
H     H 

However,  the  conversion  is  not  direct  for  the  lactose  is  first  changed  by 
enzymes  into  glucose  and  galactose  from  which  the  lactic  acid  is  produced. 
In  the  ordinary  souring  of  milk  several  other  bodies  besides  lactic  acid  are 
formed  by  the  breaking  down  of  the  milk  sugar. 

Hexose  Sugar. — Jones,  acting  on  a  suggestion  of  Theobald  Smith, 
has  recently  reached  the  conclusion  that  there  is  a  trace  of  hexose  sugar 
in  normal  milk  and  that  it  may  come  from  the  decomposition  of  lactose 
into  galactose,  or  more  probably,  may  be  derived  from  the  cow's  blood. 

Salts  in  Milk. — The  salts  of  milk  have  not  been  fully  studied;  sodium, 
potassium,  calcium,  magnesium,  chlorides,  phosphates  and  sulphates 
are  commonly  found,  as  well  as  traces  of  iron,  citrates  and  salts  of  organic 
acids.  To  some  extent  the  salts  are  ionized.  Some  chemists  express 
the  results  of  their  analyses  conventionally  in  the  form  of  oxides,  not 
meaning  to  imply  thereby  that  the  mineral  constituents  actually  so 
exist  in  milk.  Others  state  them  in  the  form  of  hypothetical  combina- 
tions which  are  purely  theoretical  for  how  these  constituents  exist  in 
milk  is  not  known.  On  burning  milk,  a  white  ash  is  left  which  does  not 
truly  represent  the  mineral  constituents  for  they  are  oxidized  in  the 
operation. 


MILK  11 

Gases. — The  gases  dissolved  in  milk  are  oxygen,  nitrogen,  and  carbon 
dioxide;  they  are  probably  absorbed  during  and  after  milking.  Decom- 
posed milk  often  contains  stinking  gases  that  are  derived  from  the 
breaking  down  of  the  proteins  which  contain  sulphur. 

Composition  and  Flow  of  Milk  Variable. — There  are  many  factors 
that  influence  both  the  amount  of  milk  flow  and  the  composition  of  milk. 
It  is  important  to  realize  this  for  the  variations  are  not  ordinarily  appar- 
ent to  our  senses  which  fact  has  fixed  in  the  minds  of  most  of  us  the  unfor- 
tunate belief  that  the  variations  are  of  minor  importance,  that  milk  is 
milk,  and  that  its  production  involves  little  skill  and  forethought.  In 
truth,  the  differences  in  milk  are  considerable  and  the  sound  management 
of  a  dairy  herd  requires  much  intelligence  as  well  as  thorough  training 
and  experience. 

Effect  of  Maltreating  Cows. — At  the  outset  it  may  be  said  that  the 
milk  business  is  founded  on  motherhood  and  that  the  dairy  cow  is  a 
high-bred,  nervous  animal  so  that  it  is  imperative  that  she  have  consider- 
ate treatment.  Cruel  and  abusive  usage  of  the  animals  is  no  part  of 
good  dairying  and  the  farmer  who  curses,  beats  or  dogs  his  cows  is  sure 
to  have  to  pay  for  it  because  such  acts  adversely  affect  both  the  quantity 
and  quality  of  milk  yielded. 

Factors  Influencing  the  Milk  Flow. — A  number  of  things  affect  the 
milk  flow.  Certain  breeds  of  cows  and  certain  individual  animals  are 
heavy  producers;  it  is  their  nature.  A  cow  at  different  ages  yields 
differently;  Eckles,  after  careful  study,  reached  the  conclusion  that  on 
the  average  a  dairy  cow  may  be  expected  to  produce  about  70  per  cent, 
as  a  2-year  old,  about  80  per  cent,  as  a  3-year  old  and  about  90  per  cent, 
as  a  4-year  old  of  the  milk  and  butterfat  that  she  will  produce  when 
mature.  The  richness  of  the  milk  remains  practically  constant  except 
that  after  the  third  milking  period  there  is.  a  slow,  gradual  decline  with 
advancing  years.  The  size  and  character  of  the  ration  affects  the 
amount  of  milk  given  and  its  character  in  less  degree.  Almost  any  change 
in  feed  has  a  slight  temporary  effect  on  the  quality  of  the  milk  but  if 
the  ration  is  sufficient,  the  quality  of  the  milk  cannot  be  markedly  or 
permanently  altered  in  this  way.  Fat  cannot  be  fed  into  milk  but  the 
quality  of  the  butterfat  is  affected  by  certain  feeds;  for  instance,  linseed 
oil  meal  and  gluten  meal  make  a  soft  oily  fat  while  cottonseed  meal, 
wheat  bran  and  some  other  feeds  make  hard  fat.  The  milk  flow  is  re- 
duced in  quantity  by  spells  of  heat  and  drouth  as  it  is  temporarily  in 
cold  snaps  and  if  the  cows  are  exposed  to  cold  wet  storms. 

Effect  of  Milking. — The  frequency  and  manner  of  milking  affect  both 
the  quantity  and  quality  of  the  milk.  If  a  cow  is  milked  three  or  four 
times  a  day  she  will  produce  more  milk,  but  with  greater  fluctuations  in 
the  percentage  of  butterfat  in  the  milk  at  the  different  milkings,  than  if 
she  is  milked  but  twice.  Cows  that  are  making  a  record  of  production 


12 


CITY  MILK  SUPPLY 


are  milked  four  times  daily.  Whether  frequent  milking  pays  depends 
on  the  value  of  the  record  and  commercially,  on  the  value  of  the  product. 
In  Denmark,  where  labor  is  cheap  cows  are  milked  thrice  daily  but  in 
the  United  States,  it  is  the  custom  to  milk  but  twice.  When  the  interval 
that  intervenes  between  milkings  is  the  same,  there  is  little  difference  in 
the  morning  and  evening  milk,  but  usually  the  period  between  the  even- 
ing and  morning  milking  is  greater  than  that  between  the  morning  and 
evening,  with  the  result  that  the  morning  milk  is  generally  somewhat 
greater  in  amount  and  runs  a  little  lower  percentage  of  butterfat  than 
the  evening  milk.  Richmond  compiled  the  average  for  17  years  of  morn- 
ing and  evening  milk  where  the  mean  intervals  of  milking  were  10.8 
and  13.2  hr.  with  the  result  given  in  Table  6. 

TABLE  6. — PERCENTAGE  COMPOSITION  OF  MORNING  AND  EVENING  MILK  1897- 

1913  (RICHMOND) 


Specific  gravity 

Total  solids 

Fat 

Solids-not-fat 

Morning  
Evening 

1.0323 
1  0319 

12.47 
12  83 

3.56 
3  93 

8.91 

8  90 

In  milking,  the  percentage  of  butterfat  increases  steadily  from  the 
first  milk  drawn  to  the  strippings,  so  that  there  is  considerable  difference 
between  the  character  of  first  and  the  last  milk  drawn.  This  is  illustrated 
by  the  figures  given  in  Table  7.  Hence  it  is  important  to  milk  out  the 
cows  thoroughly  to  get  the  rich  milk.  Moreover,  if  this  is  not  done,  the 
level  of  production  of  the  herd  tends  to  drop. 

TABLE  7. — AVERAGE  PERCENTAGE  OF  CONSTITUENTS  OF  FOREMILK  AND  STRIPPINGS 

(ECKLES  AND  $HAW) 


Total 
protein 

Sugar 

Fat 

Ash 

Total  solid 

Relative  size 
of  fat 
globules 

Foremilk. 

3.58 

5.30 

1.87 

0.75 

10.67 

139 

Stoppings  , 

3.38 

5.33 

6.28 

0.70 

14.86 

215 

Variation  in  Milk  from  Milking  to  "Milking. — Eckles  and  Shaw  found 
that  the  milk  of  a  single  cow  from  milking  to  milking  is  subject  to  the 
following  variations.  The  protein  varied  little,  for  no  sample  varied 
0.3  per  cent,  from  the  average  of  the  animal  supplying  the  samples  and 
over  90  per  cent,  of  the  samples  showed  a  variation  of  less  than  0.2  per 
cent,  from  the  average.  Only  exceptionally  would  such  variations  be 
of  moment  from  the  food  standpoint.  The  sugar  is  commonly  held  to 
be  the  least  variable  constituent  of  milk  but  it  was  found  to  vary  more 
than  the  protein.  The  milk  of  some  animals  showed  a  much  wider 


MILK 


13 


variation  than  that  of  others.  About  90  per  cent,  of  the  analyses  showed 
a  variation  of  less  than  0.2  per  cent.;  in  certain  cow's  milk  a  variation 
of  0.5  per  cent,  was  not  uncommon.  The  butterfat  varied  most,  the 
extreme  being  about  2  per  cent,  and  only  56  per  cent,  of  the  samples 
were  within  0.3  per  cent,  of  the  average;  27.7  per  cent,  varied  between 
0.6  and  0.9  per  cent,  and  4.6  per  cent,  varied  more  than  0.9  per  cent. 
The  investigators  concluded  that  a  sample  taken  from  a  single  milking 
gives  little  indication  of  the  quality  of  milk  produced  by  any  cow. 

The  variation  in  the  fat  content  of  individual  cows  was  investigated 
by  Anderson  also.  His  results  are  given  in  Table  8,  wherein  all  those 
animals  that  had  a  range  of  not  more  than  1  per  cent,  of  butterfat  are 
grouped  as  one  class;  e.g.,  an  animal  testing  as  low  as  3.2  per  cent,  and 
as  high  as  4.1  per  cent,  would  range  0.9  per  cent,  butterfat  and  would  be 
jisted  in  class  1;  class  2  would  have  a  range  of  1.8  per  cent,  and  so  forth. 

TABLE  8. — VARIATION  IN   BUTTERFAT   CONTENT   OF   MILK   OF   INDIVIDUAL   Cows 

(ANDERSON) 


Class  according  to  range  of  variation  of  per- 

centage of  butterfat  in  milk 

Records 

1 

2 

3 

4 

5 

6 

0-1 

1.1-2 

2.1-3 

3.1-4 

4.1-5 

5.1-6 

200  7-day  records,  herd  conditions  : 

Number  of  cows  in  each  class  

55 

88 

43 

8 

3 

1 

Percentage  of  cows  in  each  class  

27.5 

44.0 

21.5 

4.0 

1.5 

0.5 

2,000  consecutive  7-day  official  records  (a)  : 

Number  of  cows  in  each  class  

569 

1,091 

268 

53 

16 

3 

Percentage  of  cows  in  each  class  

28.45 

54.55 

13.40 

2.65 

0.80 

0.15 

600  2-day  records,  herd  conditions: 

Number  of  cows  in  each  class  

446 

121 

28  ' 

3 

2 

Percentage  of  cows  in  each  class  

74.3 

20.1 

4.6 

0.5 

0.3 

2,000  Jersey  and   Holstein-Friesian   2-day 

records  (6): 

Number  of  cows  in  each  class 

1,323 

514 

127 

27 

8 

1 

Percentage  of  cows  in  each  class  

66.1 

25.7 

6.4 

1.4 

0.4 

0.0 

(a)  A  few  Jersey  records  included;  the  rest  are  Holstein. 

(6)  1,000  2-day  semiofficial  records  of  Jersey  cows  on  register  of  merit  tests  and 
1,000  2-day  semiofficial  records  of  Holstein-Friesian  cows. 


The  7-day  records  in  Table  8  indicate  that  about  50  per  cent,  of  a 
herd  would,  in  7  days,  show  a  range  of  variation  in  butterfat  of  1.1  to  2 
per  cent.;  about  30  per  cent,  of  them  would  show  a  range  of  0  to  1  per 
cent.;  about  14  per  cent,  would  show  a  range  between  2.1  to  3  per  cent, 
and  the  remaining  6  per  cent,  would  show  even  greater  variation.  On 
the  basis  of  the  2-day  test  it  would  appear  that  about  66.66  per  cent,  of  the 
animals  would  show  a  range  of  variation  of  from  0  to  1  per  cent,  of  butter- 


14  CITY  MILK  SUPPLY 

fat,  20  to  25  per  cent,  a  range  of  1.1  to  2  per  cent,  of  butterfat;  5  per  cent, 
a  range  of  2.1  to  3  per  cent,  of  butterfat  and  the  rest  still  wider  variation. 

Individuality  of  the  Cow  and  the  Production  of  Butterfat. — The  indi- 
viduality of  the  cow  has  a  determining  influence  on  the  quality  of  milk. 
The  percentage  of  fat  in  the  milk  of  one  cow  may  be  high,  and  that  of 
another  one  low,  for  no  other  reason  than  that  it  is  the  nature  of  the  beasts. 
The  tendency  to  produce  rich  milk  is  hereditary  and  does  not  always 
come  from  the  female  line ;  the  influence  of  a  bull  of  good  milking  ancestry 
in  raising  the  fat  test  of  the  herd  is  well  recognized  and  is  taken  advan- 
tage of  by  wide-awake  dairymen  in  building  up  their  herds.  In  the 
Dairy  Record  Center  at  Farmers  Union,  Ontario,  there  were  14  herds, 
seven  of  which  had  been  improved  by  the  use  of  purebred  sires  and  the 
other  seven  of  which  had  always  used  grade  sires.  The  former  group 
with  82  cows,  had  an  average  production  of  7,901  Ib.  of  milk  a  year, 
while  the  latter  group  with  84  cows  had  one  of  only  4,712  Ib.  The  dif- 
ference in  production  per  cow  of  3,187  Ib.  of  milk  divided  a  profit  of 
$2,646.87  among  the  owners  or  $378.12  additional  to  each  man. 

Effect  of  the  Condition  of  the  Cow  at  Calving. — Eckles  has  shown  that 
a  cow  that  is  fat  at  calving,  will  yield  milk  for  20  to  30  days,  and 
in  some  cases,  for  as  long  as  4  months,  that  will  test  higher  than 
her  milk  does,  when  she  calves  in  poor  condition.  This  is  so,  because 
the  cow  in  fat,  converts  her  body  fat  to  butterfat.  The  practical  signifi- 
cance of  this  is,  that  it  pays  a  dairyman  to  bring  a  cow  to  calving  in 
good  condition,  that  he  may  reap  extra  profits  from  her  high-testing  milk. 
Another  point  is  that  it  is  possible  to  deceive  the  unwary  by  selling  a 
cow  on  a  butterfat  test  that  is  considerably  higher  than  her  average  for 
the  year,  because  it  was  made  soon  after  calving. 

Changes  in  the  Character  of  Milk  during  the  Lactation  Period. — 
Besides  the  variations  in  the  milk  of  the  individual  cow  there  are  those 
of  a  more  general  character  that  arise  from  the  regimen  of  the  milk 
flow,  the  seasonal  changes  and  the  breed  of  the  cows. 

Eckles  and  Shaw  have  shown  that  in  the  course  of  a  lactation  period 
there  are  three  stages. 

"The  first  covers  a  period  of  3  to  6  weeks  and  runs  from  the  time  milk  secre- 
tion begins  until  it  reaches  normal.  The  period  is  characterized  by  high  protein 
and  ash  content  of  the  milk  for  4  to  5  days,  a  decline  in  protein  and  fat  for  3  to 
6  weeks  and  by  very  large  fat  globules  which  grow  small  rapidly. 

"The  second  stage  begins  with  the  close  of  the  first,  when  the  milk  becomes 
normal  and  extends  over  a  variable  period,  usually  6^  months,  to  the  time 
when  the  milk  yield  begins  to  fall  off  rapidly,  which  usually  occurs  6  to  8  weeks 
before  the  close  of  the  lactation  period.  During  this  period  the  composition  of 
the  milk  is  uniform. 

"The  third  stage  is  sometimes  sharply  defined  and  sometimes  the  change  is 
gradual.  It  begins  6  to  8  weeks  before  the  close  of  the  lactation  period.  The 


MILK 


15 


milk  changes  decidedly  in  composition.  The  percentage  of  protein  and  fat  rises 
rapidly.  The  total  protein  may  be  one-third  higher  than  at  the  middle  of  the 
lactation  period  but  the  proportion  of  casein  and  albumin  remains  unchanged. 
The  butterfat  changes  decidedly  both  as  to  the  size  of  the  globules  and  chemic- 
ally. Toward  the  end  of  the  lactation  period  the  cream  becomes  difficult  and 
even  impossible  to  churn.  The  milk  of  some  of  the  cows  develops  an  abnormal 
flavor  and  odor." 

Seasonal  Variation  in  Composition. — Not  only  does  the  character 
of  milk  change  with  the  advance  of  the  lactation  period  but,  as  Richmond 
has  shown,  it  exhibits  a  distinct  seasonal  variation  in  quality.  The  year 
can  be  divided  roughly  into  four  periods  thus: 

1.  November,  December,  and  January;  the  milk  is  rich  in  fat  and 
solids-not-fat. 

2.  February,  March  and  April;  the  solids  do  not  show  appreciable 
diminution  but  the  fat  becomes  less  in  quality. 

3.  May,  June,  July  and  August;  the  fat  is  low  though  there  is  a  tend- 
ency for  it  to  rise  at  the  end  of  the  period.     In  July  and  August  the 
solids-not-fat  are  below  average. 

4.  September  and  October;  an  improvement  in  quality  both  in  fat 
and  in  solids-not-fat  occurs. 

Breed  of  Cow  and  Production  of  Butterfat. — That  the  breed  of  cows 
influences  both  the  quality  and  quantity  of  milk  produced  has  long  been 
known.  Table  9,  compiled  from  the  analyses  of  Lythgoe  of  the  Massa- 
chusetts State  Board  of  Health,  those  of  the  New  York  and  of  the  New 
Jersey  Agricultural  Experiment  Stations,  gives  an  idea  of  how  breed 
affects  the  quality  of  milk. 

TABLE  9.— AVERAGE  COMPOSITION  OF  THE  MILK  OF  SEVERAL  BREEDS  OF  CATTLE 


Breed 

Analyst 

Number 
of 
samples 

Fat 

Sugar 

Pro- 
tein 

Ash 

Total 
solids 

Solids- 
not-fat 

Ratio, 
pro- 
tein 
to 

Ratio, 
fat  to 
solids- 
not-fat 

fat 

Jersey  

Lythgoe  

36 

5.65 

4.94 

3.46 

0.72 

14.75 

9.10 

0.61 

0.62 

Guernsey  

Lythgoe  

28 

5.23 

4.84 

3.73 

0.75 

14.60 

9.37 

0.71 

0.56 

Devon  

New  York  Ag. 

72 

4.15 

5.07 

3.76i 

0.76 

13.77 

9.62 

0.43 

Expt.  Sta. 

Ayrshire 

LythcoG  . 

27 

4.01 

4.88 

2.99 

0.76 

12.64 

8.63 

0.75 

0  46 

Shorthorn  

New  Jersey  Ag. 

3.65 

4.80 

3.27 

0.73 

12.45 

8.80 

0.89 

0.41 

Expt.  Sta. 

Dutch  Belted.. 

Lythgoe  

41 

3.56 

4.93 

2.96 

0.70 

12.15 

8.59 

0.83 

0.44 

American     Hol- 

New  York  Ag. 

124 

3.55 

5.01 

3.391 

0.70 

12.63 

9.08 

.... 

0.39 

derness  

Expt.  Sta. 

Holstein  

Lythgoe  

56 

3.41 

4.70 

2.93 

0.74 

11.69 

8.18 

0.86 

0.41 

1  Casein. 

It  is  apparent  that  the  breed  of  cattle  has  an  important  relation  to 
milk  quality.     The  total  solids  which  in  a  general  way  represent  availa- 


16  CITY  MILK  SUPPLY 

ble  nutriment  are  considerably  greater  in  some  of  the  milks  than  in 
others  and  the  tendency  is  for  the  fat  and  protein  to  increase  together 
from  the  low  solids  milk  to  the  high.  However,  they  do  not  increase  at 
equal  rates  as  the  column  headed  protein  fat  ratio  shows.  All  of  these 
things  are  important  to  those  who  produce  and  those  who  consume  milk 
and,  therefore,  affect  the  price  at  which  it  sells. 

The  chemical  constituents  of  milk  that  have  been  described  make  up 
its  nutrients  and  determine  its  food  value.  Until  recently  the  quality 
of  milk  was  judged  solely  by  the  percentage  of  these  components  that  it 
carried  but  in  this  country  about  1890  a  new  criterion  of  milk  quality 
was  introduced.  Questions  began  to  be  asked  about  its  bacterial  content. 
Interest  in  this  subject  had  been  long  in  developing.  In  the  period  from 
1857  to  1873  Pasteur,  Lister  and  others  had  finally  convinced  people  that 
the  souring  of  milk  was  due  to  lactic  acid  bacteria  and  by  1881  it  began  to 
be  generally  accepted  that  infectious  diseases  are  carried  in  milk.  About 
this  time  the  specific  germs  of  these  maladies  began  to  be  isolated  so 
that  the  public  became  accustomed  to  the  idea  that  such  germs  occasion- 
ally got  into  milk  but  the  demonstration  that  market  milk  contained 
large  numbers  of  germs  of  different  sorts  amazed  people  and  led  bacteri- 
ologists to  study  the  role  they  played.  It  was  soon  found  that  bacteria 
did  affect  milk  in  various  ways  and  that  its  flavor  and  keeping  quality 
might  be  improved  by  cleanly  methods  of  dairying  and  by  keeping  milk 
cold  to  prevent  the  multiplication  of  the  germs  that  in  one  way  and 
another  got  into  it.  Clean  and  cold  became  the  watchword  of  progressive 
dairymen  and  of  all  those  who  were  endeavoring  to  improve  market  milk. 
The  importance  of  bacteriology  to  the  milk  industry  was  further  increased 
by  the  discovery  that  pure  cultures  of  bacteria  might  be  used  commer- 
cially to  improve  the  flavor  of  manufactured  dairy  products  and  to  make 
artificial  buttermilk  and  other  milk  beverages  which  were  steadily  growing 
in  popularity.  So,  in  order  to  get  a  correct  conception  of  the  city  milk 
problem,  the  relation  of  bacteria  to  dairying  must  be  briefly  considered. 

Bacteria  in  Milk. — Milk  as  it  comes  from  the  udder  generally  con- 
tains but  few  bacteria.  They  are  germs  that  have  worked  their  way  up 
the  teat  canal  and  have  established  themselves  in  the  milk  cistern  and  the 
several  ducts  leading  therefrom.  Relatively  few  forms  are  able  to  ha- 
bituate themselves  to  the  specialized  conditions  of  life  that  continued  exist- 
ence within  the  udder  imposes.  The  organisms  that  do  so,  constitute  a 
very  small  but  the  only  fixed  part  of  the  bacterial  content  of  milk  which, 
except  for  these  types,  is  composed  of  a  mixture  of  divers  microbes  from 
many  sources.  Since  milk  is  an  excellent  culture  medium,  a  large  per- 
centage of  the  microbes  that  chance  to  fall  therein  grow  vigorously; 
consequently  it  has  no  characteristic  bacterial  flora  but  rather  one  that 
is  a  composite  of  all  the  germ  life  with  which  it  has  had  contact.  It  is 
true  that  certain  forms  such  as  Strept.  lacticus  somewhat  constantly  set 


MILK  17 

up  a  definite  series  of  changes  in  milk  but  even  these  are  to  be  accounted 
for  rather  in  the  fact  that  they  are  commonly  found  in  the  surroundings 
with  which  milk  comes  into  touch  than  that  milk  is  their  natural  habitat. 

Classification  of  Bacteria  Found  in  Milk. — While  the  bacteria  in 
milk  are  a  heterogenous  lot  it  is  possible  to  separate  them  into  groups  and 
it  is  helpful  to  do  so  for  it  simplifies  the  problem  they  present  by  enabling 
one  to  clearly  distinguish  the  useful  and  important  organisms  from  those 
that  are  hurtful  and  those  not  of  material  interest.  There  are  several 
classifications,  but  that  in  Table  10,  a  slight  modification  of  that  of 
Hastings,  is  believed  to  be  as  serviceable  as  any. 

Importance  of  the  Various  Classes  of  Bacteria. — With  regard  to  the 
classes  as  a  whole  it  may  be  said  that  in  the  first,  the  organisms  of  groups 
1  and  2  are  most  important.  They  are  the  ones  that  effect  the  ordinary 
souring  of  milk;  the  value  of  the  product  is  in  no  small  degree  determined 
by  which  of  them  participates  most  fully  in  the  process.  The  bacteria 
of  the  first  group  give  milk  a  pleasant  mildly  acid  flavor,  whereas  those 
of  the  second  give  it  a  sharp  tang  and  other  tastes  of  a  less  definite 
character.  Moreover,  the  microbes  of  the  second  group  are  the  par- 
ticular enemies  of  the  cheese  maker,  because  they  are  the  cause  of 
gassy  curds.  When  slovenly  conditions  surround  the  production  of  milk, 
manure  and  dust  in  which  these  microbes  abound,  will  get  into  the  milk 
in  large  quantities,  and  heavily  seed  it  with  the  organisms.  They  are 
best  controlled  by  scrupulous  attention  to  cleanliness  and  keeping 
the  milk  well  cooled.  As  a  rule  organisms  of  group  2  outnumber  those 
of  group  1  at  the  outset,  but  are  soon  overgrown  by  the  latter.  In  fine, 
the  effect  of  these  organisms  is  to  keep  milk  from  putrefying;  were  it 
not  for  them,  bacteria  of  the  second  class  would  find  ample  opportunity 
for  development,  and  milk  would  be  more  perishable  than  it  now  is,  and 
its  consumption  would  be  attended  with  a  certain  sort  of  danger  from 
which  it  is  now  largely  free.  Bacteria  of  the  third  group  have  rapidly 
acquired  commercial  importance  since  their  discovery.  Lang  has  shown 
that  they  are  particularly  adapted  for  culturing  buttermilk  that  is 
obtained  from  churning  pasteurized  cream. 

The  bacteria  of  class  2  are  wholly  objectionable;  not  only  do  they 
produce  bad  flavors  in  milk  but  they  rot  it  and  produce  decomposition 
products  that  arouse  suspicion  because  they  are  evolved  from  proteins. 
Moreover  it  is  all  but  certain  that  some  of  these  germs  are  the  cause  of 
serious  intestinal  disturbances  in  children.  Their  presence  in  milk  is 
believed  to  indicate  uncleanly  methods  of  production.  The  pasteuriza- 
tion of  milk  at  high  temperature,  by  killing  off  all  vegetative  forms  and 
the  lactic  acid  bacteria  in  particular,  may  give  an  opportunity  for  these 
putrefactive  forms  to  develop,  which  is  one  reason  that  has  brought  the 
"holder"  process  of  pasteurizing  into  favor. 

The  microbes  of  class  3  betray  their  presence  to  the  consumer;  con- 


18  CITY  MILK  SUPPLY 

sequently  he  avoids  milks  affected  by  them.  They  often  cause  producers 
much  annoyance  and  some  loss. 

Bacteria  of  class  4  are  unimportant.  It  is  different  with  the  germs 
of  class  5.  These  disease-producing  organisms  effect  no  changes  in 
milk  that  would  warn  the  consumer  of  their  presence.  When  they  are 
considered  on  the  basis  of  the  frequency  with  which  they  occur  in  milk 
they  are  not  impressive,  but  when  thought  of  in  relation  to  the  havoc 
they  have  wreaked  on  customers,  the  worry  and  monetary  burdens  they 
have  imposed  on  the  dairy  industry  and  the  financial  loss  and  ruin  they 
have  caused  dairymen  their  consequence  becomes  momentous.  In 
times  bygone  the  very  lack  of  knowledge  of  pathogenic  organisms  was 
a  contributive  factor  to  the  loss.  Happily,  this  handicap  has  been  all 
but  removed  and  effective  means  of  protecting  the  industry  and  populace 
from  ravages  of  this  sort  are  indicated. 

Stages  in  the  Bacterial  Decomposition  of  Milk. — The  highest  grades 
of  milk  may  contain  few  bacteria  other  than  the  udder  types  but  as  milk 
is  ordinarily  produced  for  the  market  it  contains  a  mixed  and  numerous 
flora,  the  subsequent  development  of  which,  as  Hastings  and  others 
have  shown,  is  determined  by  a  number  of  factors,  important  among 
which  are  the  character  and  amount  of  the  initial  seeding  and  the  tem- 
perature at  which  the  milk  is  held.  The  marked  tendency  of  the  lactic 
acid  bacteria  to  outstrip  other  forms  at  temperatures  between  50°  and 
67.5°F.  normally  causes  a  sequence  of  changes  in  which  there  are  four 
principal  stages. 

First  Stage. — The  first  of  these  is  known  as  the  germicidal  stage  and 
lasts  for  only  a  short  time  after  the  milk  is  drawn  from  the  udder.  Bac- 
terial counts  made  at  frequent  intervals  during  the  first  few  hours,  not 
over  24,  show  progressively  fewer  colonies.  There  is  much  difference 
of  opinion  among  bacteriologists  concerning  the  nature  of  the  phe- 
nomenon. Some  would  account  for  the  decrease  in  numbers  on  the  ground 
that,  though  milk  is  a  favorable  culture  medium  for  many  germs,  it  is 
not  for  all,  and  consequently  those  for  which  it  is  unsuited  die  off.  Others 
believe  that  milk,  like  the  blood  and  many  body  fluids,  has  bactericidal 
power,  though  they  admit  it  is  weak  and  soon  lost.  Rosenau  and  others 
believe  that  the  force  is  not  bactericidal  but  agglutinative;  that  the 
bacteria  are  not  killed  but  are  gathered  in  clumps  from  which,  on 
the  plates,  single  colonies  arise,  instead  of  many  as  there  would  if  the 
clumps  dispersed. 

All  are  agreed  that  for  a  short  time  after  milk  is  drawn  there  is  a 
period  wherein  the  number  of  germs  does  not  increase  but  rather  tends 
to  fall  off.  It  seems  that  at  high  temperature,  98°F.  for  instance,  the 
action  is  marked  but  is  over  in  8  to  10  hr.;  at  low  temperatures  the  action 
is  not  so  decided  but  is  more  prolonged.  The  power  is  lost  in  24  hr.  or 
if  the  newly  drawn  milk  is  heated  to  176°F.  This  latter  fact  has  been 


MILK  19 

urged  against  pasteurization  but  the  "holder"  process  does  not  attain 
this  temperature.  After  the  germicidal  stage  is  passed,  the  bacteria 
increase  continuously  and  with  great  rapidity.  The  practical  impor- 
tance of  the  germicidal  period  is  that  it  may  be  turned  to  account  by 
promptly  finishing  the  necessary  handling  and  cooling  of  the  milk.  In 
other  words,  milk  has  a  temperature  of  about  100°F.  when  taken  from 
the  cow,  and  if  allowed  to  stand  around  on  a  hot  summer  day  or  in  a 
warm  room  will  not  cool  down  very  much,  so  that  the  germicidal  period 
may  pass  and  rapid  bacterial  multiplication  may  actually  set  in  before 
cooling  and  bottling  the  milk  is  begun. 

Second  Stage. — The  second  stage  extends  from  the  end  of  the  germi- 
cidal period  to  the  time  of  curdling.  Once  the  germicidal  period  is 
passed,  the  lactic  acid  bacteria,  group  1,  increase  rapidly  both  in  numbers 
and  relatively  to  the  other  germs  which  for  a  while  may  multiply,  but 
not  so  fast  as  the  lactic  acid  organisms.  Before  long,  the  acidity  which 
this  group  of  bacteria  produces  becomes  so  great  that  other  forms  are 
checked  except  that  microbes  of  group  2,  the  coli-aerogenes  group,  may 
continue  to  develop  unless  the  temperature  of  the  milk  is  kept  below 
64 °F.  If  this  is  done  the  true  lactic  acid  organisms  will  crowd  out  prac- 
tically all  other  organisms  and  increase  to  many  millions  at  curdling. 

Third  Stage. — The  third  stage  extends  from  the  time  of  curdling  to 
the  time  acidity  is  neutralized.  When  loppering  takes  place,  the  acidity 
is  so  high  that  the  lactic  acid  germs  begin  to  decrease  and  thereafter 
continue  to  fall  off.  Oidium  lactis,  certain  moulds  and  yeasts  which  have 
been  in  the  milk  from  the  start,  grow  in  the  highly  acid  medium  and 
by  attacking  the  proteins  reduce  it  to  a  neutral  or  alkaline  condition. 

Fourth  Stage. — Final  decomposition  changes  are  effected  by  liquefy- 
ing and  peptonizing  bacteria  that  heretofore  have  been  inactive.  They 
find  the  alkaline  condition  favorable  for  growth  and  assail  the  casein 
with  avidity,  accomplishing  the  ultimate  decompositional  changes. 

Bacterial  Decomposition  of  Milk  Usually  Harmless. — All  of  this 
must  make  it  obvious  that  the  development  of  bacteria  in  milk  is  a 
perfectly  normal  process  akin  to  others  that  take  place  wherever  organic 
matter  is  undergoing  decomposition.  It  is  evident,  too,  that  the  process 
is  not  ordinarily  fraught  with  danger  to  man.  The  harmless  lactic  acid 
bacteria  usually  carry  the  disintegration  to  the  point  where  milk  becomes 
inedible.  It  is  relatively  exceptional  for  putrefying  or  peptonizing 
organisms  to  play  the  master  part  in  milk  decomposition  and  the  germs 
of  communicable  disease  gain  access  to  milk  comparatively  infrequently. 
Still,  experience  teaches  that  there  is  a  real  danger  in  impure  milk,  and 
in  the  United  States  and  elsewhere  it  is  customary  to  spend  large  sums  of 
money  in  seeing  that  adequate  safeguards  attend  the  production  and 
marketing  of  milk.  Of  those  milks  that  are  looked  upon  as  being  unsafe, 
it  is  usual  to  distinguish  two  sorts,  namely:  (1)  dirty  and  (2)  infected  milk. 


20  CITY  MILK  SUPPLY 

Dirty  Milk. — With  regard  to  dirty  milk,  undoubtedly  one  of  the  chief 
reasons  why  it  is  held  in  disfavor  is  that  the  very  idea  of  consuming  food 
that  is  unclean  is  repugnant  to  most  people.  In  some  quarters  there 
has  been  a  tendency  to  make  light  of  this  feeling  as  being  merely  an 
appeal  to  the  fastidious.  In  reply  it  has  been  well  said  that  the  eyes, 
the  nose  and  the  tongue  were  given  men  to  use  and  that  foods  which 
do  not  appeal  to  the  senses  are  depreciated  in  market  value.  However, 
if  esthetic  desire  is  given  free  rein  it  will  lead  to  inordinate  extravagance 
and  perverted  taste.  The  demand  for  foods  put  up  in  fancy  styles  in 
costly  containers  and  the  penchant  for  colored  foods,  bleached  preserves 
and  polished  rice  are  illustrations  of  these  tendencies.  So  with  milk, 
the  striving  for  cleanliness  may  be  pushed  to  the  point  where  it  costs 
more  than  the  benefit  it  yields  is  worth  and  the  search  for  the  last  germ 
becomes  a  craze.  Great  quantities  of  dirty  milk  are  consumed  daily 
by  adults  without  apparent  harm  but  physicians  regard  dirty  milk  as 
distinctly  injurious  to  babies  because  their  tender  mucous  membranes 
are  unfit  to  cope  with  the  millions  of  bacteria  that  it  contains.  Rpsenau 
gives  five  definite  reasons  why  dirty  milk  may  hurt  infants,  viz.: 

1.  "  Ordinary  dirt  may  contain  yeasts  that  cause  fermentation  in  the  bowels, 
distending  them  with  gas,  producing  paralysis  in  them  and  even  causing  death. 

2.  "It  contains  B.  subtilis  which  may  set  up  putrefaction  in  the  intestinal 
tract  and  which  has  been  found  in  excessive  numbers  in  many  cases  of  gastro- 
intestinal disturbances  of  children. 

3.  " B.  welchii  which  is  ordinarily  found  in  common  dirt  may  cause  fatal  diar- 
rhea in  babies  and  even  in  adults  and  may  excite  irritation  and  dysentery. 

4.  "  Tubercle  bacilli  get  into  milk  in  cow  dung  and  so  may  other  germs  that 
ordinarily  do  not  particularly  harm  an  adult  but  may  overwhelm  an  infant. 

5.  "There  may  be  toxic  substances  formed  in  milk.     Dirty  milk  may  not  be 
poisonous  but  it  is  apt  to  be." 

From  an  industrial  standpoint  dirty  milk  is  highly  objectionable. 
It  yields  a  gassy  curd  and  is  likely  to  cause  off  flavors,  consequently 
cheese  from  such  milk  brings  low  prices.  Dirty  milk  and  cream  entail 
severe  losses  on  the  butter  trade  because  butter  made  from  dirty  cream 
does  not  grade  high  in  the  market  and  so  has  to  be  sold  cheap.  The 
production  of  large  quantities  of  such  cream  has  played  into  the  hands 
of  foreign  manufacturers  who  find  it  easy  to  compete  with  the  poor 
butter  that  results  from  its  use.  The  evil  has  become  so  serious  that  in 
the  Middle  West  active  efforts  are  being  made  to  curb  it. 

Infected  Milk. — Infected  milk  carries  specific  disease-producing 
bacteria  and  causes  cases  or  outbreaks  of  communicable  disease.  While 
such  milk  is  relatively  unusual  it  is  of  immense  importance  and  the  desire 
to  diminish  the  opportunities  of  its  occurrence  has  had  great  weight  in 
framing  milk  ordinances  and  food  laws. 

To  summarize :  the  souring  and  spoiling  of  milk  is  not  a  result  brought 


MILK  21 

about  by  anything  inherent  in  milk  itself,  but  is  caused  by  germs  of 
various  sorts  that  are  introduced  to  the  milk  and  grow  therein,  liberating 
enzymes  and  other  byproducts  that  disintegrate  the  milk.  To  man 
these  organisms  are  not  ordinarily  harmful  but  on  the  contrary  are  on 
the  whole  protective,  and  are  productive  of  various  changes  that  are 
essential  to  the  manufacturers  of  milk  drinks,  butter  and  cheese.  It  is 
true  that  some  of  the  bacteria,  the  pathogenic,  that  develop  in  milk  are 
highly  injurious  to  man,  but  these  organisms,  though  of  enormous  import- 
ance, should  be  regarded  as  occurring  exceptionally,  and  should  not 
be  permitted  to  make  one  forget  that  other  bacteria,  such  as  those  of 
the  lactic  acid  and  of  the  Bulgaricus  groups,  when  controlled  by  scientific 
methods,  are  made  to  perform  important  and  useful  service  to  the  dairy 
industry. 

Grading  of  Milk. — This  discussion  of  the  chemical  constituents  of  milk 
and  of  the  changes  wrought  in  it  by  bacteria  must  make  it  apparent  that 
there  is  great  difference  in  the  quality  of  milks  and  hence  in  their  value. 
This  raises  the  question  as  to  how  the  value  of  milk  shall  be  determined. 
Until  within  a  few  years  there  has  been  no  effort  to  meet  this  question; 
so  long  as  a  milk  met  the  legal  standard  for  butterfat  and  total  solids  and, 
in  some  places,  did  not  exceed  the  limit  set  for  bacterial  count  every  one 
was  satisfied.  Milk  was  sold  by  the  quart  regardless  of  its  quality.  The 
effect  of  this  was  bad  because  the  dairyman  who  sold  clean,  rich  milk  had 
to  compete  at  equal  prices  with  the  one  who  sold  milk  that  was  not  so  clean 
and  rich.  This  amounted  to  unfair  competition  because  sanitation  costs 
money  and  rich  milk  is  more  expensive  to  produce  than  poor  milk  since 
the  cows  that  give  rich  milk  do  not  produce  as  heavily  as  those  that 
give  milk  of  low  test.  The  consequence  was  that  the  heavy-producing 
cows  of  the  low-testing  breeds  began  to  displace  the  others  and  dairymen 
felt  it  a  hardship  to  have  to  comply  with  -sanitary  regulations.  Gradu- 
ally contractors  adopted  the  plan  of  paying  premiums  for  milk  testing 
above  a  certain  amount,  for  milk  produced  in  clean  stables  and  for  milk 
delivered  with  a  low  bacterial  count.  It  became  apparent  that  milk 
should  be  bought  and  sold  on  a  quality  basis  so  that  the  dairyman 
might  produce  the  sort  of  milk  he  wished  and  the  consumer  might  buy 
the  sort  he  fancied  and  could  afford.  This  has  led  some  communities- 
to  attempt  to  grade  milk,  so  that  the  people  might  buy  grade  A  and  grade 
B  milk,  just  as  they  would  buy  firsts  or  seconds  in  apples  and  other  agri- 
cultural products.  The  matter  of  grading  milk  is  discussed  in  Chapter  7. 
Here  it  merely  desired  to  point  out  that  in  establishing  grades  of  milk 
there  will  have  to  be  considered:  (1)  its  nutritive  value  as  judged  by  the 
butterfat  and  solids-not-fat;  (2)  its  sanitary  value  as  indicated,  by  its 
freedom  from  dirt  and  low  bacterial  count;  and  (3)  its  palatability  as 
evidenced  by  its  acidity  and  flavor.  Moreover,  whether  it  comes  from 
tuberculin-tested  cows  or  is  properly  pasteurized  will  have  to  be  taken 
into  account. 


22 


CITY  MILK  SUPPLY 


Besides  the  ordinary  milk  that  is  used  in  a  city,  there  are  consumed 
quantities  of  modified  milk,  milk  beverages,  condensed  milk  and  milk 
powder.  These  will  be  briefly  considered. 

Modified  Milk. — The  milk  of  every  species  of  animal  is  peculiar  to 
its  kind  as  Table  11  indicates,  and  is  adapted  to  the  needs  of  its  growing 
young  as  Table  12  shows.  Those  animals  like  the  seal,  dolphin  and  whale 
whose  young  have  to  develop  a  large  amount  of  blubber  very  quickly 

TABLE  11. — PERCENTAGE  COMPOSITION  OF  THE  MILK  OF  SOME  ANIMALS 


Water 

Fat 

Sugar 

Casein 

Albumin 

Ash 

Ass  
Bitch 

90.12 
75  44 

1.26 
9  57 

6.50 
3  09 

1.32 
6  10 

0.34 
5  05 

0.46 
0  73 

Buffalo  
Camel 

82.63 
86  57 

7.61 
3  07 

4.72 
5  59 

3.54 
4 

0.60 
01 

0.90 
0  77 

Caribao  
Cat 

78.46 
81  63 

10.35 
3  33 

4.32 
4  91 

5.35 
3  12 

0.53 
5  96 

0.84 
0  58 

Cow  
Elephant 

87.32 
67  85 

3.75 
19  57 

4.75 

8  84 

3.00 
3 

0.40 
00 

0.75 
0  65 

Ewe..  
Gamoose1  

79.46 
84.10 

8.63 
5.56 

4.28 
5.41 

5.23 
3.26 

1.45 
0.60 

0.97 
1.03 

Goat  

86  04 

4  63 

4  22 

3  49 

0.86 

0.76 

Llama 

86  55 

3  15 

5  60 

3  00 

0  90 

0  80 

Mare  

89  80 

1  17 

6  89 

1 

.81 

0.30 

Mule  

91.50 

1.59 

4.80 

1 

.64 

0.38 

Porpoise 

41  11 

48  50 

1  33 

11 

.19 

0.57 

Rabbit 

69  50 

10  45 

1  95 

15 

54 

2  56 

Reindeer  . 

57  80 

17  10 

2  80 

8  40 

2  00 

1.50 

Sow  

84.04 

4.55 

3.13 

7 

.23 

1.05 

Whale  .  . 

48  67 

43  67 

7 

11 

0.46 

Wmoan  

88.20 

3.30 

6.80 

1.00 

0.50 

0.20 

Zebu  

86  13 

4  80 

5  34 

3 

03 

0.70 

1  Egyptian  Water  Buffalo. 
TABLE  12. — PERCENTAGE  COMPOSITION  OF  MILK  IN  RELATION  TO  GROWTH  (HAWK) 


Animal 

Time  in  days  in 
which  the  newborn 
doubles  its  weight 

Protein 

Ash 

Calcium 

Phosphoric 
acid 

Man  .         .  . 

180  0 

1   6 

0  2 

0  033 

0.047 

Horse  

60  0 

2.0 

0.4 

0.124 

0.131 

Calf  

47  0 

3  5 

0  7 

0.160 

0.197 

Kid 

22  0 

3  7 

0  8 

0  197 

0.284 

Lamb  

15  0 

4.9 

0.8 

0.245 

0.293 

Pig  

14.0 

5.2 

0.8 

0.249 

0.308 

Cat 

9  5 

7  0 

1  0 

Doe. 

9  0 

7  4 

1.3 

0.455 

0.508 

Rabbit  

6.0 

10.4 

2.5 

0.891 

0.997 

MILK 


23 


secrete  milk  rich  in  fat  while  those  whose  offspring  make  rapid  growth 
secrete  milk  high  in  protein  and  mineral  matter. 

In  a  sense  every  animal  that  is  fed  on  the  milk  of  another  species  is 
given  artificial  food;  in  fact  the  only  common  substitution  that  is  made 
is  that  of  the  cow  for  that  of  the  woman  and  even  this  is  attended  with 
difficulties  for  there  are  marked  differences  in  the  two  milks  as  Table 
13  shows.  To  lessen  the  troubles  that  arise  from  feeding  cow's  milk 
to  babies  it  is  often  modified,  or  made  to  approach  that  of  the  woman  in 
character. 

TABLE  13. — WOMAN'S  MILK  AND  Cow's  MILK  CONTRASTED  (ROTCH) 


Woman's  milk 


Cow's  milk 


1.  Reaction 

2.  Water.: 

3.  Mineral  matter.. . 

4.  Total  solids 

5.  Fats.. 


6.  Milk  sugar .  .  . 

7.  Proteins 

8.  Caseinogen . . . 


9.  Whey  products 


10.  Coagulable  proteins 

11.  Coagulation  of  protein 
by  acids  and  salts 

12.  Coagulation  of  proteins 
by  rennet 

13.  Action  of  gastric  juice. 


Amphoteric  (more  alkaline 

than  acid). 
87-88  per  cent. 
0.2  per  cent. 
13  to  12  per  cent. 
4  per  cent. ;  relatively  poor 

in  volatile  glycerides. 
7  per  cent. 
1.5  per  cent. 
One-third  to  one-half  of  the 

total  proteins. 
Two-thirds  to  one-half  of 

the  total  proteins. 
Small  proportionately. 
With     greater     difficulty; 

curds  small  and  Succulent. 

Does  not  coagulate  readily. 
Proteins   precipitated   but 

easily  dissolved  in  excess 

of  the  gastric  juice. 


Amphoteric  (more  acid  than 

alkaline). 
86-87  per  cent. 
0.7  per  cent. 
14-13  per  cent. 
4  per  cent.;  relatively  rich 

in  volatile  glycerides. 
4.75  per  cent. 
3.5  per  cent. 
2.66  per  cent. 

0.84  per  cent. 

Large  proportionately. 
With  less  difficulty;  curds 
large  and  tenacious. 


Coagulate  readily. 
Proteins    precipitated 
dissolved  less  readily. 


but 


Modified  milk  was  first  prepared  for  sale,  by  the  Walker-Gordon 
Laboratory  Co.  under  the  direction  of  Dr.  T.  M.  Rotch,  in  Boston,  Mass., 
in  1891. 

It  is  manifestly  impossible  to  so  modify  cow's  milk  that  it  will  be 
woman's  milk;  all  that  is  feasible  is  to  make  the  percentages  of  the 
principal  components  of  the  two  correspond  and  to  replace  the  casein 
with  whey  protein.  The  modifications  of  cow's  milk  that  are  commonly 
made  are,  to  reduce  the  protein  and  increase  the  sugar  to  correspond  with 
the  respective  percentages  of  these  elements  in  human  milk.  In  addi- 
tion, 25  to  50  per  cent,  of  lime  water  is  often  added  to  increase  the  alka- 
linity of  the  milk  and  so  to  prevent  or  delay  the  formation  of  curds  by 


24 


CITY  MILK  SUPPLY 


the  action  of  rennin  of  the  stomach,  the  percentage  of  fat  is  sometimes 
changed,  the  casein  replaced  by  whey  protein  and  sometimes  a  soluble 
starch  is  added  to  the  amount  of  0.75  per  cent,  in  some  such  form  as  barley 
water  to  act  as  a  protective  colloid  to  prevent  the  formation  of  large 
casein  curds.  Further  modifications  may  be  made  if  the  condition  of  the 
child  seems  to  the  physician  to  demand  it.  Modification  may  be  made 
in  the  laboratories  of  certified  and  other  milk  companies  but  such  milk 
is  too  costly  for  many  and  so  modifications  are  made  in  the  home  according 
to  simple  rules  or  formulas  supplied  by  the  physician. 


Courtesy  of  Stephen  Francisco. 

FIG.  1. — Modifying  milk  at  the  Fairfield  Dairy,  Montclair,  N.  J. 

Milk  Beverages. — The  milk  beverages  are  buttermilk,  keffir,  ku- 
miss, yoghurt,  matzoon  and  others  less  well  known  to  the  public.  But- 
termilk is  the  milk  left  in  the  churn  in  the  manufacture  of  butter.  There 
are  two  kinds,  namely,  that  resulting  from  churning  sweet  cream  and  that 
from  sour  cream.  The  former  is  practically  skim-milk  while  the  latter  has 
undergone  lactic  fermentation  and  acquired  an  agreeable  acid  flavor. 
Buttermilk  usually  carries  small  flakes  of  butter;  the  churning  breaks  up 
the  curd  and  the  acid  alters  the  casein  so  that  it  is  no  longer  acted  on  by 
acid;  therefore  it  cannot  form  tough  lumps  in  the  stomach.  Artificial 
buttermilk  or  cultured  or  ripened  milk  as  it  is  sometimes  called  forms  a 
large  part  of  the  buttermilk  sold  in  the  big  cities.  It  is  not  made  by 


MILK  25 

churning  cream  but  by  souring  milk  and  stirring  it  to  break  up  the  curd. 
Some  dealers  inoculate  the  sweet  milk  with  a  small  quantity  of  skim- 
milk  that  has  been  allowed  to  sour  spontaneously  and  speak  of  the  product 
as  naturally  soured,  while  others  use  bacterial  cultures  to  effect  souring. 

Keffir  is  the  fermented  milk  of  the  Caucasus  and  was  one  of  the 
first  fermented  milks  known  to  Europeans.  Fermentation  by  the 
natives  is  brought  about  by  keffir  grains,  small  yellow  warty  nuggets 
that  contain  bacteria  and  yeast  cells.  These  grains  effect  both  an  acid 
and  a  mild  alcoholic  fermentation  of  the  milk.  In  this  country  keffir  is 
made  by  adding  cane  sugar  to  milk  and  fermenting  it  in  bottles  with  a 
lactic  culture  and  bread  yeast.  The  quantity  of  sugar  added  determines 
the  percentage  of  alcohol  in  the  finished  product;  the  addition  of  1  per 
cent,  of  sugar  produces  a  keffir  carrying  about  0.5  per  cent,  of  alcohol. 

Kumiss  is  the  fermented  milk  drink  of  the  people  of  southern  Russia, 
Siberia  and  Central  Asia.  Like  keffir  it  is  a  mildly  alcoholic  acid  drink 
that  is  much  esteemed  for  invalids.  It  is  said  that  the  best  kumiss  is 
made  in  the  province  of  Orenburg  in  Russia  at  Odessa,  Samara  and  Ufa, 
in  establishments  under  medical  charge. 

Yoghurt  is  the  fermented  milk  drink  of  the  Bulgars  and  Turks  while 
Matzoon  is  that  of  the  Armenians.  These  beverages  are  non-alcoholic 
and,  according  to  Rogers,  are  made  by  inducing  fermentation  by  B. 
bulgaricus. 

All  of  these  beverages  are  sold  by  dealers  in  this  country.  Sometimes 
they  are  put  out  under  their  proper  names  and  sometimes  under  ones  of 
the  dealers  choosing.  These  drinks  are  wholesome  and  they  make  a  valu- 
able addition  to  the  American  dietary.  Sometimes  they  are  taken  for 
the  health,  but  whenever  they  are  so  used,  they  should  be  taken  as  pre- 
scribed by  a  physician. 

Condensed  Milk  and  Milk  Powder. — Condensed  milk  and  milk  pow- 
der form  an  important  part  of  the  milk  supply  of  our  cities.  Bakers, 
confectioners  and  ice-cream  makers  use  them  in  large  quantities  and  in 
the  home,  condensed  milk  is  used  as  a  substitute  for,  or  to  supplement, 
the  regular  milk  supply.  These  products  can  only  be  touched  on  here 
for  they  are  more  properly  treated  in  a  book  on  dairy  manufactures. 

The  extent  to  which  condensed  milk  enters  into  domestic  use  is  not 
precisely  known  for  there  have  been  few  investigations  of  the  matter. 
It  is  used  because  some  people  prefer  it  to  milk,  because  others  consider 
it  safer  than  milk  and  because  most  people  find  it  a  convenience  since 
it  does  not  have  to  be  kept  on  ice.  Dealers  distinguish  several  different 
kinds  of  condensed  milk  but  it  is  unnecessary  for  the  general  public  to 
know  more  than  two,  viz.,  sweetened  condensed  milk  and  evaporated 
milk. 

Sweetened  condensed  milk  is  made  by  adding  12  to  18  per  cent,  of 
cane  sugar  to  milk  and  evaporating  it  in  vacuo  till  the  finished  product 


26  CITY  MILK  SUPPLY 

has  been  condensed  in  the  ratio  of  2.5  parts  of  fresh  milk  to  1  of  condensed. 
In  the  process  the  milk  is  not  heated  high  enough  to  kill  the  moulds  and 
bacteria  that  are  in  the  milk  but  the  syrupy  consistency  of  the  finished 
product  usually  keeps  them  from  developing.  However,  when  the  milk 
is  diluted  for  use  they  may  grow.  The  addition  of  sugar  to  the  milk 
before  it  is  condensed  makes  this  sort  of  milk  radically  different  from 
cow's  milk. 

In  manufacturing  evaporated  milk  no  sugar  is  added.  The  milk  is 
condensed  in  the  ratio  of  about  2.5  : 1  and  is  afterward  sterilized  at  228° 
to  236°F.  or  at  even  higher  temperature.  This  high  temperature  gener- 
ally makes  the  milk  sterile  but  it  precipitates  most  of  the  albumin  in  the 
milk  and  very  probably  affects  the  milk  sugar  so  that  the  evaporated 
milk,  too,  is  quite  different  from  cow's  milk. 

Milk  powder  is  a  recent  comer  to  the  market  but  it  has  found  a  ready 
market  and  many  believe  that  it  will  have  an  important  influence  on  the 
city  milk  trade.  The  chief  difficulty  that  it  has  had  to  meet  is  that  the 
less  stable  fatty  acids  of  butterfat  decompose  in  light  and  air  with  the 
production  of  a  tallowy  flavor.  Powdered  skim-milk  does  not  have  to 
contend  with  this  obstacle  and  so  is  a  success.  Milk  powders  are  not 
sterile  but  they  are  protected  against  the  action  of  microbes  by  their 
lack  of  moisture.  As  they  absorb  moisture  on  exposure  to  the  air  they 
are  kept  in  parchment-lined  cartons  or  barrels. 

Sources 

LEACH,  "Food  Inspection  and  Analysis."  2nd  Ed.,  1909,  pp.  124-208. 

WING,  "Milk  and  its  Products,"  1913,  pp.  16-34. 

WARD,  "Pure  Milk  and  the  Public  Health,"  1909,  pp.  174-185. 

VAN  SLYKE,  "  Modern  Methods  of  Testing  Milk  Products,"  1913. 

FARRINGTON  and  WOLL,  "Testing  Milk  and  its  Products,"  1912. 

WILCOX,  "Production  and  Inspection  of  Milk,"  Hawaii  Ag.  Expt.  Sta.,  1912. 

INGLE,  "Manual  of  Agricultural  Chemistry,"  1902,  pp.  197-233. 

SAVAGE,  "Milk  and  the  Public  Health,"  1912,  pp.  1-16. 

" Hygienic  Laboratory  Bulletin   56,"  U.    S.    Public    Health   and    Marine    Hospital 

Service,  1909. 

RICHMOND,  "Dairy  Chemistry,"  1914. 
MICHELS,  "Market  Dairying  and  Milk  Products,"  1912. 
BARNHART,  J.  M.,  "The  Composition  of  Milk." 
ANDERSON,  "Studies  in  the  Range  of  Variation  of  the  Per  cent,  of  Butterfat  in 

Milk  of  Individual  Cows,"  Bull.  71,  Mich.  Ag.  College. 
ECKLES,  "Influence  of  Fatness  of  Cow  at  Parturition  on  Per  Cent,  of  Fat  in  Milk," 

Bui.  100  Missouri  Ag.  Expt.  Sta. 
ECKLES  and  SHAW,    "Influence   of  Stage   of  Lactation   on   the   Composition   and 

Properties  of  Milk,"  Bui.  155  B.  A.  I.,  U.  S.  Dept.  of  Ag. 
SHAW  and  ECKLES,  "A  Chemical  and  Physical  Study  of  the  Large  and  Small  Fat 

Globules  in  Cow's  Milk,"  Bui.  Ill,  B.  A.  I.,  U.  S.  Dept.  of  Ag. 
ECKLES  and  SHAW,  "The  Influence  of  Breed  and  Individuality  on  the  Composition 

and  Properties  of  Milk,"  Bui  156,  B.  A.  I.,  U.  S.  Dept.  of  Ag. 


MILK  27 

Farmer's  Bulletin  14,  U.  S.  Dept.  of  Ag. 

Hoard's  Dairyman,  11,  Sept.  14;  25,  Sept.  14;  30,  Oct.  14. 

WILLOUGHBY,  "Milk,  its  Production  and  Uses,"}  1904. 

ECKLES,  "Dairy  Cattle  and  Milk  Production,"  1914. 

HAGGARD,  "Rural  Denmark  and  its  Lessons,"   1913. 

PALMER  and  ECKLES,  "The  Principal  Natural  Color  Pigment  in  Milkfat,  etc."  Jour. 

of  Biological  Chemistry,  vol.  18,  p.  191,   1914. 
JONES,  "The  Bacterial  and  Chemical  Evidence  of  a  Hexose  Sugar  in  Normal  Milk." 

Jour.  Infectious  Diseases,  vol.  15,  No.  2,  1914. 
THOMPSON,  "Information  Concerning  Milch  Goats,"  Bui.  68  B.  A.  I.,  U.  S.  Dept.  of 

Agriculture,  1905. 

CONN,  "The  Fermentation  of  Milk,"  Expt.  Sta.  Bull.  9,  U.  S.  Dept.  Ag. 
KENDALL,  DAY  and  WALKER,  "Studies  in  Bacterial  Metabolism,  31-38,"  Jour.  Am. 

Chem.  Soc.,  1914. 
KENDALL,  DAY  and  WALKER,  "Studies  in  Bacterial  Metabolism,  7,"  Jour.  Biolog. 

Chem.,  vol.  13,  No.  1,  October,  1912. 

HEINEMANN,  "Kinds  of  Bacteria  Concerned  in  Souring  Milk,"  Univ.  of  Chicago,  1907. 
ESTEN,  "Bact.  Lactis  Acidi  and  Its  Sources,"  Bull.  56,  Storrs  Ag.  Expt.  Sta.,  1909. 
HASTINGS,  HAMMER  and  HOFFMAN,  "Studies  on  the  Bacterial  and  Leucocyte  Content 

of  Milk,"  Res.  Bull.  6,  Univ.  Wis.  Ag.  Expt.  Sta.,  1909. 
HEINEMANN  and  HEFFERNAN,  "A  Study  of  B.  Bulgaricus,"  Jour.  Infect.  Diseases, 

vol.  6,  No.  3,  June,  1909,  pp.  304-318. 
HEINEMANN  and  GLENN,  "Experiments  on  the  Germicidal  Action  of  Cow's  Milk," 

Jour.  Infect.  Diseases,  vol.  5,  No.  5,  pp.  534r-541,  December,  1908. 
HARDING  and  WILSON,  "A  Study  of  the  Udder  Flora  of  Cows,"  Tech.  Bull.  27,  N.  Y. 

Ag.  Expt.  Sta.,  1913. 

HAWK,  "Practical  Physiological  Chemistry,"  3d  Ed.,  1910. 
JORDAN,   "General  Bacteriology,"   4th  Ed.,    1914. 
BUCHANAN,  "Household  Bacteriology,"  1913. 
MARSHALL,  "Microbiology,"  1912. 
ROSENAU,  "The  Milk  Question,"  1912. 
SAVAGE,  "Milk  and  the  Public  Health,"  1912.       . 
HUNZIKER,  "Condensed  Milk  and  Milk  Powder,"  1914. 
LARSEN  and  WHITE,  "Dairy  Technology,"  1914. 
ROGERS,  "Fermented  Milks,"  Bull.  319,  U.  S.  Dept.  Ag.,  1916. 
DOUGLAS,  "The  Bacillus  of  Long  Life,"  1911. 
WILLIAMS,  "The  Economic  Problems  of  Milk  Distribution  in  the  Relation  to  the 

Public  Health,"  Trans.  15th  International  Congress  of  Hygiene  and  Demography, 

Washington,  D.  C.,  1912. 
MERRITT,  "The  Production  and  Consumption  of  Dairy  Products,"  BuU.  177,  U.  S. 

Dept.  Ag.,  1915. 

Farmer's  Bull.  575,  U.  S.  Dept.  Ag.,  "Live  Stock  of  the  United  States." 
LYTHGOE,  "  The  Composition  of  Milk  as  Shown  by  Analyses  of  Samples  of  Known 

Purity,"  Jour,  of  Indust.  and  Eng.  Chemistry,  vol.  6,  No.  11,  p.  899,  1914. 


CHAPTER  II] 
DISEASES  COMMUNICABLE  IN  MILK 

Wherever  men  have  been  living  together,  destruction  by  pestilence 
has  been  going  on.  Of  the  nature  of  this  mysterious  foe  man  could  but 
speculate  in  bewildered  terror.  The  savage  thought  the  sick  possessed 
of  demons;  among  more  advanced  peoples  the  religious  looked  on  afflic- 
tions of  this  sort  as  visitations  from  God  for  sin.  Slowly  with  the  emerg- 
ing of  medicine  from  empiricism  to  a  science,  more  materialistic  explana- 
tions were  advanced  and  belief  in  the  supernatural  gave  way.  In  the 
period  from  1815  to  1835  the  achromatic  objective  was  invented  and  the 
compound  microscope  perfected  so  that  man  had  a  new  weapon  at  his 
disposal,  one  that  made  the  enemy  visible.  From  this  time  on  rapid 
progress  was  made  in  the  acquisition  of  exact  knowledge  concerning 
contagion.  Discoveries  in  microbiology  led  to  the  isolation  of  the  specific 
germs  of  diseases  so  that  it  was  possible  to  interpret  observations  that 
were  made  on  the  mode  of  transmission  of  these  maladies  more  accurately, 
but  prevailing  ideas  had  to  be  abandoned  or  considerably  changed  before 
the  truth  was  reached.  In  the  latter  part  of  the  19th  century  the  filth 
theory  of  disease  obtained  wide  credence;  it  was  briefly  that  disease  germs 
were  created  out  of  filth  or  decomposing  matter.  Practically,  it  led  to 
the  cleaning  up  of  many  foul  places  but  it  did  not  prove  sound  and  only 
in  a  greatly  modified  form  is  it  now  applied,  yet  testimony  of  the  hold  it 
took  is  to  be  found  in  the  fact  that  even  now  the  public  has  faith  in  pro- 
tective health  measures  that  have  nothing  besides  this  outgrown  theory 
to  recommend  them.  As  this  conception  of  the  way  in  which  contagion 
is  engendered  was  given  up,  there  was  substituted  the  belief  that  it  was  the 
offspring  of  environment;  and  air,  food,  water  and  clothing  were  looked 
upon  as  being  the  sources  whence  it  sprang.  This  proved  to  be  only  a 
part  of  the  truth  for  it  has  been  found  that  it  is  exceptional  for  the  virus 
of  disease  to  remain  long  alive  in  these  things  and  within  the  last  decade 
their  importance  as  sources  of  contagion  have  been  minimized.  It  is 
now  believed  that  the  body  itself  is  the  fountain  head  of  infection.  It  is 
the  various  discharges  of  the  organism  that  are  dangerous  and  the  study 
of  outbreaks  of  contagion  is  largely  a  study  of  the  way  saliva,  urine,  feces 
and  other  excretions  are  circulated  in  the  affected  community.  To  a  less 
extent  man  is  infected  by  animals  and  through  the  bites  of  insects  but 
even  so  the  morbific  principle  is  transferred  by  a  more  or  less  direct  route 
from  the  sick  to  the  well.  It  is  the  ailing  beast  or  man  that  is  the  poten- 

28 


DISEASES  COMMUNICABLE  IN  MILK  29 

tial  source  of  infection  in  others.  Speaking  by  and  large,  disease  germs 
do  not  live  long  outside  the  body;  they  are  parasites  and  cannot  thrive 
without  the  host.  As  a  rule  they  do  not  live  long  and  do  not  multiply 
in  water  and  in  foods;  these  serve  merely  as  the  vehicle  which  transfers 
them  from  one  being  to  another  and  the  shorter  the  journey  the  more 
likely  is  the  microbe  to  arrive  in  virulent  condition. 

Milk  a  Vehicle  of  Infection. — For  a  long  time  milk  escaped  suspicion 
of  being  a  conveyor  of  infection  but  in  1857  Dr.  Michael  W.  Taylor  traced 
an  outbreak  of  typhoid  fever  in  Penrith,  England,  to  it.  Ten  years  lapsed 
before  an  epidemic  was  again  laid  to  milk,  then  in  1867  Taylor  found 
another  epidemic  in  Penrith,  this  time  of  scarlet  fever,  was  due  to  milk. 
In  1872  Macnamera  held  an  infected  dairy  in  Calcutta,  India,  responsible 
for  Asiatic  cholera  and  in  1877  Dr.  Jacob  determined  that  a  milk  supply 
at  Sutton,  Surrey,  England,  caused  diphtheria.  Thus  milk  was  impli- 
cated in  the  transmission  of  four  of  the  principal  communicable  diseases. 
Notwithstanding  the  evidence  that  was  then  advanced  a  portion  of  the 
medical  profession  remained  skeptical  as  to  milk  being  concerned  and 
dairymen  were  more  than  loath  to  accept  the  finding.  The  contentions 
of  Taylor  and  the  others  were  sustained  in  1881  by  a  paper  read  by 
Ernest  Hart  before  the  International  Medical  Congress  of  that  year, 
wherein  he  gave  an  account  of  50  epidemics  of  typhoid  fever,  15  of  scarlet 
fever  and  four  of  diphtheria  that  were  caused  by  milk.  The  paper  clinched 
the  matter.  Since  then  so  much  confirmatory  evidence  has  accumulated 
that  it  is  almost  universally  believed  that  milk  does  carry  several  of 
the  most  important  contagious  diseases.  Such  milk,  that  carrying  the 
specific  virus  of  communicable  disease,  is  called  infected  milk. 

Discovery  of  Disease  Germs. — In  the  early  eighties  discoveries  were 
made  that  enabled  those  who  believed  that  milk  was  at  times  responsible 
for  the  spread  of  contagion  to  speak  out  unequivocally,  and  at  the  same 
time  present  the  case  to  the  public  in  tangible  form.  In  1882  Koch 
brought  out  solid  culture  media  which  so  advanced  the  technique  of 
bacteriologists,  that  soon  afterward  the  specific  germs  of  several  of  the 
diseases  were  isolated  and  grown  outside  the  body.  The  bacillus  of 
diphtheria  was  discovered  in  1883,  that  of  Asiatic  cholera  in  the  same 
year,  that  of  tuberculosis  in  1884  and  that  of  typhoid  fever  which  was 
first  observed  in  1880  was  grown  for  the  first  time  in  1884. 

So  it  was  possible  to  inoculate  these  disease  germs  in  milk  and  observe 
how  they  behave.  It  was  found  they  all  live  in  milk  and  with  the 
exception  of  B.  tuberculosis  all  multiply  in  it.  Milk  is  as  good  food  for 
pathogenic  and  many  other  bacteria  as  it  is  for  man;  they  thrive  in  it 
which  explains  why  a  very  slight  infection  is  serious  and  why  diluting 
the  infection  by  adding  pure  milk  to  that  which  contains  the  germs  does 
not  materially  lessen  the  danger  of  drinking  such  milk,  after  it  has  stood 
awhile,  as  dilution  of  infected  water  with  pure  does. 


30 


CITY  MILK  SUPPLY 


Classification  of  Milk-borne  Diseases. — Diseases  that  man  contracts 
from  milk  are  of  two  classes,  namely: 

Class  I. — Diseases  of  animal  origin. 

A.  Definite  diseases :  tuberculosis,  foot-and-mouth  disease,  Malta  fever 
and  anthrax.  B.  Indefinite  ailments :  diarrheal  infections  and  possibly 
contagious  abortion. 

Class  II. — Diseases  of  human  origin:  typhoid  fever,  paratyphoid 
fever,  diphtheria,  scarlet  fever,  tuberculosis,  Asiatic  cholera,  septic  sore 
throat  and  possibly  others. 

Tuberculosis. — Of  all  the  diseases  transmitted  by  milk,  tuberculosis 
is  the  most  important  both  because  of  the  frequency  with  which  it  is  con- 
veyed and  because  of  its  serious  nature.  The  tuberculosis  that  is  derived 
from  milk  may  be  either  of  human  or  bovine  origin.  Human  infection  of 
milk  is  rarer  than  bovine  and  in  practically  every  case,  except  conceiv- 
ably from  air  or  flies,  comes  from  some  one  that  is  handling  the  milk 
and  has  the  disease.  A  tuberculous  milker  who  spits  on  his  hands  has 
every  opportunity  to  wash  the  germs  into  the  milk  and  the  spray  that  is 
ejected  in  the  cough  of  a  consumptive  milk  handler  may  fall  into  the  milk 
and  infect  it.  Hess  in  1908  in  New  York  City  actually  isolated  the 
human  tuberculosis  bacillus  from  a  sample  of  market  milk.  However, 
danger  from  this  source  is  relatively  small  and  is  controllable  so  that 
human  tuberculosis  is  of  less  importance  so  far  as  milk  is  concerned 
than  the  tuberculosis  that  is  of  bovine  origin. 

TABLE  14. — TABULATION  OF  PARK  AND  KRUMWIEDE'S  TUBERCULOSIS  CASES 


Diagnosis  of  cases  examined 

Adults  16  years 
and  over 

Children 
5  to  16  years 

Children  under 
5  years 

Human 

Bovine 

Human 

Bovine 

Human 

Bovine 

Pulmonary  tuberculosis 

281 

1 
9 

1 

•• 

8 
4 
19 

1 

8 

1 

7 

6 

1 
1 
18 
25 
26 
7 

13 
3 
2 
4 

1 
2 

Tuberculous  adenitis,  inguinal  and  axillary  
Tuberculous  adenitis,  cervical 

Abdominal  tuberculosis 

Generalized  tuberculosis   alimentary  origin 

Generalized  tuberculosis 

2 
305 

1 

1 

2 
10 

1 

•     • 

Generalized  tuberculosis  including  meninges  
Tubercular  meningitis  

Tuberculosis  of  bones  and  joints  

Genito-urinary  tuberculosis  

Tuberculosis  of  skin 

Tuberculosis  of  abscess 

Totals 

1 

46 

9 

91 

25 

In  1901  Koch  announced  that  there  was  practically  no  danger  of 
man  contracting  tuberculosis  from  cattle.  The  statement  was  at  once 
challenged  and  many  bacteriologists  set  themselves  to  find  out  the 
truth  of  the  matter.  To  date  the  reports  of  the  English  Royal  Com- 
mission, of  the  German  Commission  and  of  Park  and  Krumwiede  in 


DISEASES  COMMUNICABLE  IN  MILK 


31 


this  country  are  the  most  valuable  contributions  to  the  subject  and  give 
fairly  clear  insight  into  the  question.  Koch's  dictum  is  proven  to  have 
been  based  on  insufficient  evidence  and  is  rejected.  A  summary  of  Park 
and  Krumwiede's  observations  together  with  their  compilations  from 
literature  of  the  work  of  other  investigators  including  that  of  the  English 
and  German  Commissions  appear  in  Tables  14  and  15.  There  was  also 
one  case  of  double  infection;  generalized  tuberculosis  including  meninges, 
13  months;  mesenteric  nodes  gave  human  type,  and  the  meningeal  fluid 
the  bovine  type.  Total  478  cases. 

TABLE  15. — 1,033  CASES  OF  TUBERCULOSIS  COLLECTED  FROM  LITERATURE  BY  PARK 

AND  KRUMWIEDE 


Diagnosis  of  cases  examined 

Adults  16  years 
and  over 

Children 
5  to  16  years 

Children  under 
5  years 

Human 

Bovine 

Human 

Bovine 

Human 

Bovine 

Pulmonary  tuberculosis     

497 
2 
27 
15 
6 
27 

3 

1 
4 
1 

5  :  1 

17 
1  :6 
3 
3  :  1 

1 

14 
3  :5 
4 
1 

25  :3 
2 
9 
3  :6 
15  :1 
46  :  10 

5 
51 
2 
20 

2 

1 

11 
7:4 
13 
2  :  1 

10 
2 

Tuberculous  adenitis,  axillary                ...        ... 

Tuberculous  adenitis,  cervical 

Generalized  tuberculous,  alimentary  origin.  
Generalized  tuberculosis  
Generalized  tuberculosis,  including  meninges,  ali- 
mentary origin       ... 

Generalized  tuberculosis;  including  meninges  

4 

... 

10 

1 
31 

1 
4 

3 
6 

Tuberculosis  of  bones  and  joints  

31 
16 
9 

1 
3 

Genito-urinary  tuberculosis  '  

Tuberculosis  of  skin  

Miscellaneous  cases  .  .         

Tuberculosis  of  tonsils     

1 

Tuberculosis  of  mouth  and  cervical  nodes  
Tuberculous  sinus  or  abscess 

1 

1 

... 

1 
201 

51 

Totals  

635 

14 

85 

37 

Mixed  or  double  infections,  10  cases. 

The  two  sets  of  cases  together  make  a  grand  total  of  1,511  cases  and 
show  the  following  results: 

Adults  16  years  and  over,  940  human;  15  bovine;  percentage  bovine  1.5. 
Children  5  to  16  years,  131  human;  46  bovine;  percentage  bovine  26.0. 
Children  under  5  years,  292  human;  76  bovine;  percentage  bovine  20.6. 
Mixed  or  double  infection,  11. 

These  figures  indicate  that  about  a  quarter  of  the  cases  of  tuber- 
culosis in  children  under  16  years  of  age  is  due  to  infection  with  the 
bovine  type  of  bacillus  and  that  the  number  of  cases  of  bovine  origin 
among  adults  is  very  small. 

The  relation  of  tuberculosis  of  bovine  origin  to  tuberculosis  in  general, 
is  hard  to  define.  It  is  estimated  that  in  the  United  States  tuberculosis 
is  the  cause  of  9  per  cent,  of  the  deaths  and  in  Germany  12  per  cent. 


32  CITY  MILK  SUPPLY 

If  only  1  per  cent,  of  these  in  this  country  were  due  to  bovine  infection 
it  would  mean  a  loss  of  1,600  lives  a  year  but  the  percentage  is  believed 
to  be  considerably  greater,  being  placed  at  7  per  cent,  by  some.  It  is 
recognized  that  in  all  probability  practically  none  of  the  pulmonary 
tuberculosis  is  due  to  bovine  bacteria  and  that  were  all  bovine  tubercu- 
losis stamped  out,  the  tuberculosis  problem  would  be  simplified  but  not 
greatly  reduced  in  magnitude.  Japan  and  other  countries,  that  are  not 
consumers  of  milk  and  dairy  products,  have  a  great  deal  of  tuberculosis. 
On  the  other  hand,  it  is  becoming  patently  evident  that  tuberculosis  of 
bovine  origin  is  largely  responsible  for  surgical  and  abdominal  tubercu- 
losis, especially  among  children.  Furthermore,  it  is  to  be  remembered 
that  practically  all  bovine  bacteria  isolated  from  infections  in  man 
were  acquired  from  the  ingestion  of  dairy  products. 

Nature  of  Tuberculosis. — Tuberculosis  like  other  diseases  has  three 
well-marked  stages,  the  prodromal  or  incubating  period,  the  period  of 
sickness,  and  the  period  of  recuperation  or  recovery.  It  differs  from  many 
other  infectious  diseases  in  that  all  of  these  periods  may  be  prolonged. 
It  is  likely  to  be  slow  and  insidious  in  sharp  contrast  to  such  diseases  as 
smallpox  and  measles  which  commonly  develop  within  2  weeks  after 
exposure  and  are  soon  over.  In  some  diseases  like  diphtheria  and  tetanus, 
the  causative  germs  elaborate  poisons  called  toxins  that  cause  the 
death  of  the  patient  unless  they  are  neutralized  in  some  manner,  but  in 
tuberculosis  the  germs  do  not  kill  in  this  way.  They  imbed  themselves 
in  the  tissues  of  an  organ  and  by  their  growth  injure  it,  of  ten  eventually 
destroying  it  and  so,  if  the  organ  is  a  vital  one,  cause  death.  Often  the 
first  warning  given  by  the  disease  is  the  impairment  of  the  function  of 
some  organ  which  makes  the  victim  feel  sick. 

After  the  germs  have  secured  lodgment  they  grow  and  produce  the 
excrescences  called  tubercles  which  are  so  characteristic  that  they  have 
given  the  name  tuberculosis  to  the  disease.  The  tubercles  are  soft  and 
cheesy  or  hard  and  calcified;  they  may  remain  isolated  or  may  be  con- 
fluent and  form  a  mass  of  corruption.  In  several  ways  the  body  tries 
to  rid  itself  of  the  invading  organisms.  One  defense  is  to  surround  the 
diseased  spot  with  a  thick  wall  of  fibrous  tissue  thereby  isolating  it  and 
arresting  its  development.  Where  this  is  successful  the  progress  of  the 
disease  is  stopped,  and  it  may  stay  arrested  for  years  during  which  time 
the  animal  may  be  a  useful  creature,  but  often  the  attempt  to  form  a  wall 
is  abortive  or  only  temporarily  successful,  the  germs  breaking  through 
the  defense  and  spreading  the  disease.  Sometimes  the  only  organ 
involved  is  that  first  attacked,  in  which  case  the  disease  is  said  to  be  local- 
ized but  often  it  spreads  to  other  organs  and  sets  up  a  generalized  infec- 
tion. Sometimes  the  tubercles  are  scattered  widely  in  the  form  of  little 
hard  bodies  like  millet  seeds  and  give  the  form  of  the  disease  known  as 


DISEASES  COMMUNICABLE  IN  MILK  33 

miliary  tuberculosis  or  galloping  consumption  the  progress  of  which  is 
very  rapid.  Sometimes  the  serous  membranes  covering  the  lungs  or 
intestines  become  seeded  with  these  grains  giving  rise  to  a  condition 
known  as  "  pearl  disease."  Neither  the  rate  of  progress  of  tuberculosis 
nor  the  time  the  sickness  will  last  can  be  predicted;  these  depend  upon  the 
stamina  of  the  host,  the  virility  of  the  bacteria,  the  massiveness  of  the 
original  infection,  and  other  factors  imperfectly  understood. 

So  long  as  the  disease  is  confined  to  bones,  glands  and  other  structures 
that  do  not  communicate  with  channels  leading  to  the  exterior  of  the 
animal,  it  is  said  to  be  closed  and  the  animal  is  regarded  as  being 
unable  to  infect  others,  but  when  structures  such  as  the  lungs,  liver, 
gall-bladder,  kidneys,  urinary  bladder,  udder,  and  genital  organs,  that 
do  lead  without  the  animal,  are  invaded  the  creature  becomes  a  highly 
dangerous  source  of  contagion  to  susceptible  beasts  and  to  man,  for  under 
such  conditions  living  germs  are  scattered  broadcast.  In  this  state  the 
animal  may  reinfect  itself,  as  for  instance,  by  inhaling  sputum  that  is 
raised  but  not  coughed  out,  thus  establishing  new  diseased  foci  in  the 
lungs  or  by  swallowing  such  sputum  it  may  set  up  infection  in  the  viscera 
or  other  parts  of  the  body. 

Entrance  of  Tuberculosis  Germs  into  the  Body. — Tuberculosis  germs 
gain  entrance  to  the  body  in  two  principal  ways:  by  being  breathed  in 
and  by  being  swallowed  with  food.  There  is  dispute  as  to  which  of  these 
modes  of  infection  is  the  commoner;  that  neither  is  infrequent  seems 
probable. 

Passage  of  Tuberculosis  Germs  from  the  Body. — The  germs  of  tuber- 
culosis are  expelled  from  the  body  in  the  sputum,  the  urine  and  feces, 
and  in  discharges  from  the  genital  organs.  The  sputum  is  infectious 
when  the  lungs  are  diseased  and  so  the  droolings  and  the  fine  spray  that 
is  ejected  when  the  animal  coughs  spread  the  disease.  Thus  the  sick 
cow  may  lick  herself  and  other  cows  or  may  "nose"  them  and  so  distrib- 
ute the  germs.  Coughing  is  likely  to  spread  contagion  to  other  animals 
especially  to  those  confined  in  adjoining  stalls.  In  fact  the  pestilence 
is  scattered  wherever  the  infected  sputum  falls,  in  the  feed,  mangers, 
salt  boxes,  watering  troughs,  on  floors  and  in  pastures.  Tubercle  bac- 
teria are  expelled  in  the  urine  when  the  kidneys  or  urinary  bladder  are 
diseased,  and  by  these  discharges  the  flanks  of  the  animals  and  the  ground 
are  infected.  The  feces  are  infected  when  the  animal  has  intestinal 
ulcers,  when  the  liver  or  gall-bladder  is  diseased,  or  the  lungs  are  so  that 
infected  sputum  swallowed  by  the  animal  is  passed.  On  some  farms 
manure  is  piled  where  cows  can  get  at  it  and  mouth  it  and  thus  infect 
themselves.  Manure  from  a  tuberculous  animal  may  infect  whatever 
it  touches  including  the  exterior  of  the  animal  itself.  So  the  hair  and 
dirt  that  falls  from  such  a  creature  into  the  milk  infects  it;  consequently 
a  cow  without  tuberculosis  of  the  udder  may  infect  milk. 


34  CITY  MILK  SUPPLY 

Infection  of  Milk  by  Germs  of  Tuberculosis  in  the  Feces. — That 
milk  might  be  infected  with  tuberculosis  by  contamination  with  the  man- 
ure of  cows  afflicted  with  the  disease,  was  pointed  out  by  Sedgwick  and 
Batchelder  in  1892  in  their  paper  on  the  bacteriological  examination  of 
the  Boston  milk  supply  but  the  gravity  of  the  menace  was  not  appre- 
ciated till  Shroeder  and  Mohler  in  1906  emphasized  its  importance. 

Efforts  have  been  made  at  Washington,  at  the  Cornell,  Minnesota, 
Nebraska  and  Illinois  Agricultural  Experiment  Stations  and  by  the 
English  Royal  commission  to  determine  the  frequency  with  which  tuber- 
cular cows  pass  the  germs  of  the  disease  in  their  f  eces.  In  the  six  instances 
147  animals  were  studied  and  16  of  them  were  proven  to  be  passing  the 
bacilli.  Eleven  of  these  reactors  were  slaughtered  and  every  one  was 
badly  tubercular;  they  all  had  abscesses  of  the  lungs,  seven  had  ulcers 
of  the  intestines  and  six  tuberculosis  of  the  liver.  Of  the  five  animals 
not  autopsied  one  was  manifestly  tubercular  and  the  others  were  not. 
From  this  series  of  experiments  it  seems  evident  that  animals  in  ad- 
vanced stages  of  tuberculosis  pass  tubercle  bacilli  in  their  feces  and  that 
animals  seemingly  in  good  health  may  do  so. 

Frequency  of  the  Infection  of  Milk  with  Tuberculosis. — The  milk  of 
tuberculous  cows  is  likely  to  contain  the  germs  of  the  disease  and  so  unless 
heated  to  a  high  enough  temperature  to  kill  them  is  a  potent  factor  in 
spreading  the  disease,  not  only  among  the  calves  and  swine  that  may  be 
reared  on  it  but  to  man  himself.  In  discussing  the  frequency  with 
which  milk  carries  tuberculosis  germs,  there  are  to  be  considered:  (1) 
milk  from  cows  having  tuberculosis  of  the  udder;  (2)  milk  of  tuberculous 
cows  without  such  a  lesion;  and  (3)  market  milk. 

There  is  no  question  at  all  as  to  whether  cows  with  tuberculous 
udders  yield  milk  that  carries  the  germs.  Authorities  are  agreed  that 
in  all  but  very  rare  cases  such  milk  contains  enormous  numbers  of  the 
germs  in  a  highly  virulent  condition.  A  cow  with  a  tuberculous  udder 
is  such  an  ugly  menace  that  she  should  be  sent  to  the  shambles  at  once. 

As  to  whether  the  milk  of  tuberculous  cows  whose  udders  are  un- 
affected is  infectious  or  not  there  is  considerable  difference  of  opinion. 
Briscoe  and  MacNeal  record  tests  of  the  milk  of  748  tuberculous  cows 
without  recognizable  disease  of  the  udder,  and  of  the  samples  tested  in 
various  ways  13 1  proved  positive.  However,  many  of  the  positive 
results  were  secured  by  early  investigators  who  doubtless  did  not  take 
elaborate  precautions  to  prevent  the  milk  becoming  infected  from  external 
sources.  In  the  later  important  work  Ostertag  at  Berlin  in  1899  exam- 
ined the  milk  of  50  cows  finding  the  milk  of  49  negative  and  one  doubtful 
and  in  1901  that  of  18  cows  was  all  negative.  Miiller  in  Germany,  in 
1899  tested  the  milk  of  nine  cows  finding  it  all  free  from  the  germs  and 
Smit  at  Rotterdam  in  1909  likewise  got  negative  results  from  the  milk 
of  35  cows.  On  the  other  hand,  DeJong  at  Leiden  in  1908  found  that 


DISEASES  COMMUNICABLE  IN  MILK 


35 


three  out  of  10  cows  that  he  examined  were  passing  tubercle  bacteria 
in  the  milk  and  also  the  British  Royal  Commission  found  two  out  of  four 
cows  with  sound  udders  to  be  passing  the  germs  in  the  milk. 

Market  milk  presents  still  a  different  aspect  because  the  germs  of 
tuberculosis  may  be  derived  not  only  from  cows  with  tuberculosis  of 
the  udder  but  from  any  animal  that  has  an  open  case,  and  even  from  hu- 
man sources.  Consequently  such  milk  might  be  expected  to  be  slightly 
infected  somewhat  constantly.  Table  16  presents  the  important  Euro- 
pean and  American  studies  of  the  frequency  of  infection  of  market  milk 
with  tubercle  bacilli. 

TABLE  16. — TUBERCLE  BACTERIA  IN  MARKET  MILK  (a) 


Date 

Place 

Investigator 

Samples 
examined 

Number 
positive 

Percentage 
positive 

1899 

England 

Macfayden 

77 

17 

22   1 

1904 

Germany  

Muller(6). 

1,596 

97 

6  2 

1904 

Germany  

Beatty(b)  

272 

27 

10  0 

1898 

Liverpool 

Delepine 

12  (a) 

22 

17  6 

1897 

Liverpool  

Hope  .  . 

228(6) 

12 

5  2 

1900 

London  

Klein  

100 

7 

7.0 

1893 

St.  Petersburg 

Scharbekow 

80 

4 

5  0 

1900 

Kiew  

Pawlowsky  . 

51 

1 

2  0 

1900 

Krakow 

Bujwid 

60 

2 

3  3 

1900 

Naples  

Marconi 

14 

7 

50  0 

1898 

Berlin  

Petri  

64 

9 

14  0 

1900 

Berlin 

Beik      * 

56 

17 

30  3 

1898 

Schev.  Gueund  

Ott.  .  . 

27 

27 

11  1 

1898 

Konigsburg 

Jaeger 

100 

7 

7  0 

1908 

Leipsic  .  .    . 

Eber 

210 

22 

10  5 

1905 

Rotterdam  

Smit..  . 

567 

14 

2  7 

1906 

Rotterdam  

Smit  

1,584 

45 

2.8 

1908 

Washington 

Anderson 

223 

15 

6  7 

1909 
1909 

Louisville  
New  York 

Field  (c)  
Hess 

119 
105 

46 
17 

29.5 
16  2 

1909 

Philadelphia  . 

Campbell 

130 

18 

13  8 

1910 

Chicago  

Tonney  

144 

15 

10  5 

1910 

Rochester 

Goler 

237 

30 

12  6 

(a)  Compiled  from  table  of  BRISCOE  and  MACNEAL  and  from  other  sources. 

(6)  Work  done  for  East  Prussian  Herd  Book  Society  with  the  object  of  detect- 
ing and  removing  cattle  with  udder  lesions. 

(c)  Tests  made  at  the  time  the  city  was  starting  a  crusade  against  slop  dairies  and 
the  figures  are  probably  too  high  to  be  applied  to  the  average  country  herd  supply- 
ing the  city.  DR.  B.  C.  FRAZIER  states  that  in  the  tuberculin  tests  of  between  600 
and  1,000  cows  in  1916  but  three  reactors  were  found. 

Of  the  Washington  investigation  it  may  be  said  that  tuberculin  tests 
of  herds  supplying  the  city  has  shown  214  reacting  animals  out  of  1,147 


36  CITY  MILK  SUPPLY 

tested  or  12.6  per  cent,  and  tests  by  the  District  Health  Department 
upon  51  herds  likewise  supplying  the  city  detected  160  reacting  animals 
out  of  1,095  tested  or  15.1  per  cent.  These  figures  were  regarded  as 
low  because  the  herds  tested  were  believed  by  their  owners  to  be  largely 
free  from  the  disease.  The  samples  of  milk  tested  by  animal  inoculation 
showed  that  11  out  of  102  dairies  or  10.7  per  cent,  were  supplying  milk 
that  contained  tubercle  bacteria. 

The  New  York  investigation  of  1909  was  undertaken  to  determine 
first,  what  percentage  of  the  milk  of  New  York  carried  tubercle  bacteria; 
second,  what  percentage  of  tubercle  bacteria  in  the  milk  are  of  human 
and  what  of  bovine  origin;  and  third,  what  effect  the  infected  milk  has 
upon  children.  The  samples  were  taken  from  40- qt.  cans  in  grocery 
stores,  dairies  and  large  milk  plants  in  various  quarters  of  the  city  and 
every  sample  was  tested  both  by  microscopical  examination  and  animal 
inoculation.  Out  of  105  successful  tests  17,  or  16.2  per  cent.,  gave  posi- 
tive results.  Eight  cultures  were  isolated  and  studied  to  determine 
whether  the  bacteria  were  of  the  human  or  bovine  variety;  it  was  found 
that  one  was  the  former  and  seven  of  the  latter  type.  Ten  of  the  17 
milk  dealers  whose  milk  gave  positive  tests  let  their  children  have  the 
milk  to  drink  raw.  These  10  dealers  had  18  children,  16  of  whom  were 
tested  with  tuberculin  with  four  reactions. 

Length  of  Life  of  Tuberculosis  Germs  Outside  the  Body. — To  deter- 
mine the  length  of  time  tuberculosis  germs  live  outside  the  animal, 
many  studies  have  been  made.  Sunlight  and  desiccation  are  the  two 
agents  that  nature  uses  most  effectively  to  destroy  microbes.  Direct 
sunlight  kills  tuberculosis  germs  in  a  few  hours  or  even  in  a  few  minutes 
when  a  culture  is  spread  out  in  a  thin  film  on  glazed  paper  or  glass  slips. 
The  organisms  live  10  or  15  times  as  long  in  diffuse  as  in  direct  light. 
There  are  many  difficulties  in  determining  the  length  of  time  bacteria 
will  withstand  drying  and  the  many  bacteriologists  that  have  investigated 
the  subject  experimentally  have  obtained  conflicting  results.  The  work 
that  has  been  published  since  1900  seems  to  indicate  that  the  germs 
naturally  placed  will  withstand  drying  for  from  a  week  to  a  couple  of 
months. 

Moore  says  that  tuberculosis  germs,  expelled  in  the  saliva  on  pastures 
where  direct  sunlight  reaches  them,  soon  perish;  that  in  fecal  matter 
where  they  are  somewhat  protected  from  sunlight  they  will  live  longer, 
that  in  mangers  in  dark  damp  stables  they  will  live  a  considerable  time 
and  that  such  stables  are  thought  to  remain  infected  several  months. 

Mode  of  Infection  of  the  Herd. — As  to  how  herds  are  infected  many 
ways  may  be  conceived  but  practically  only  two  are  important:  the 
disease  may  be  introduced  (1)  with  certain  feeds,  particularly  with  skim- 
milk  or  whey  returned  unsterilized  from  creameries  and  cheese  factories, 
or  (2)  by  buying  the  disease  through  the  purchase  of  diseased  stock. 


DISEASES  COMMUNICABLE  IN  MILK 


37 


As  illustrative  of  the  danger  of  this  first  mode,  the  data  collected  by 
Russell  are  convincing;  they  appear  in  Table  17. 

TABLE.  17. — THE  RELATION  BETWEEN  UNSTERILIZED  SKIM-MILK  FROM  CREAMERIES 
AND  BOVINE  TUBERCULOSIS  (RUSSELL) 


Creamery 

Number 
of  herds 
tested 

Number 
of  herds 
reacting 

Number 
of  animals 
tested 

Per  cent, 
of  react- 
ng  animals 

Results  of  slaughter 

Number 
passed 

Number 
condemned 

Medina  .    .  .        

36 
24 
66 
12 

33 
14 

42 
8 

784 

429 
1,249 
218 

34.5 
24.0 
8.5 
10.0 

105 

34 

123 
61 

Oak  Park 

Group  A1     .          ...      ... 

Group  B2  

1  Group  A  comprises  seven  creameries  immediately  adjacent  to  Medina  and  Oak 
Park. 

2  Group   B  comprises  four  creameries  near  but  not  contiguous  to  Medina  and 
Oak  Park. 

The  reacting  animals  in  the  herds  of  the  Medina  and  Oak  Park 
creameries  were  nearly  all  raised  on  the  farm  and  were  fed  skim-milk 
returned  in  an  unsterilized  condition  from  the  two  creameries  whereas 
the  reactors  in  groups  A  and  B  were  mostly  acquired  by  outside  purchase. 

The  buying  in  of  tuberculosis  has  been  very  common  in  the  past. 
Some  dairymen  have  been  so  blinded  to  aught  but  immediate  gain,  as  to 
purchase  cows  they  knew  were  diseased,  carrying  them  through  a  milking 
period  and  thereafter  sending  them  to  the  block;  others  unaware  or  un- 
able to  appreciate  what  they  were  doing  have  brought  diseased  animals 
into  their  herds  with  the  result  that  as  the  newcomers  developed  open 
cases  and  became  germ  scatterers  others  succumbed.  In  truth,  cows 
with  open  cases  are  the  most  effective  disseminators  of  the  disease.  Ex- 
perience has  proven  that  bovine  tuberculosis  is  most  prevalent  in  dis- 
tricts supplying  the  city  milk  trade.  Cows  are  pushed  to  the  limit  of 
production  and  farmers  feel  that  they  must  sell  every  drop  of  milk ;  con- 
sequently calves  are  not  raised,  so  that  replacements  and  additions  to 
the  herds  are  made  by  purchase.  This  constant  movement  of  cattle 
from  one  herd  to  another  has  had  the  effect  of  spreading  the  disease  more 
rapidly  than  under  the  natural  condition  where  the  herd  practically 
maintained  itself. 

The  Diagnosis  of  Tuberculosis. — The  question  arises,  how  it  may  be 
determined  whether  or  not  a  dairy  animal  has  tuberculosis?  Four 
methods  of  diagnosis  are  in  use,  namely:  (1)  microscopical  examination  of 
excised  tissue  which  is  obviously  of  limited  application;  (2)  microscopical 
and  bacteriological  examination  of  discharges  of  various  sorts  from  the 
suspected  animal,  procedures  of  wider  use  but  time-consuming  and  often 


38 


CITY  MILK  SUPPLY 


uncertain;  (3)  physical  examination;  and  (4)  the  tuberculin  test.  The 
great  bulk  of  testing  is  done  by  the  last  two  methods. 

Physical  Examination. — The  detection  of  the  disease  by  physical 
examination  is  based  on  the  fact  that  as  the  disease  progresses  certain 
symptoms  become  manifest  to  the  trained  observer.  Of  course,  in  time 
these  become  obtrusively  evident  but  at  first  they  may  be  difficult  to 
detect  as  must  be  apparent  when  it  is  remembered  that  many  of  the  organs 
commonly  attacked  are  impossible  to  get  at.  A  persistent  cough,  en- 
larged glands,  tendency  to  be  in  heat  frequently  and  alternating  constipa- 
tion and  diarrhea  make  even  the  layman  suspicious  but  these  signs  are 
also  symptoms  of  other  diseases  and  may  mislead  any  but  the  professional. 
Moore  gives  the  impression  that  physical  examination  is  used  a  great  deal 
more  in  Europe  than  in  the  United  States  and  that  veterinarians  there 
are  far  more  expert  in  this  sort  of  diagnosis  than  Americans  are.  Some 
hold  that  frequent  and  thorough  physical  examinations  will  keep  a  herd 
free  from  open  cases  of  tuberculosis  and  that  thereby  the  spread  of  the 
disease  may  be  controlled,  with  the  result  that  the  infected  market  milk 
may  be  kept  down  to  a  minimum  quantity. 

As  evidence  against  this  contention  the  number  of  positive  results 
in  the  " control"  samples  of  Sheffield,  England,  may  be  cited.  Savage  says 
that  samples  are  taken  of  the  milk  coming  to  the  city  from  outsic  e  sources 
and  are  bacteriologically  examined  and  that  when  tubercle  bacteria  are 
found,  the  farms  supplying  the  samples  are  visited  by  a  skilled  veterinary 
inspector  who,  in  case  no  cows  are  found  having  tuberculosis  of  the  udder 
takes  "control"  samples  to  check  up  the  work  of  the  veterinarian. 
Therefore,  such  samples  are  of  the  mixed  milk  of  herds  of  cows  without 
clinical  signs  of  tuberculosis.  Table  18  shows  the  results  of  such 
examinations. 


TABLE  18. — REPORT  ON 


'CONTROL"  SAMPLES  BY  MEDICAL   HEALTH  OFFICERS  OF 
SHEFFIELD  (SAVAGE) 


Year 

Number  of  control 
samples  taken 

Number 
tuberculous 

Percentage 
tuberculous 

1902 

1 

1903 

7 

1904 

11 

3 

27.3 

1905 

17 

6 

35.3 

1906 

8 

1 

12.5 

1907 

39 

8 

20.5 

1908 

62 

7 

11.2 

1909 

56 

8 

14.3 

1902-09 

201 

33 

16.4 

So,  on  an  average  in  16.4  per  cent,  of  the  samples,  tubercle  bacteria  were 


DISEASES  COMMUNICABLE  IN  MILK  39 

found  in  the  herd  milk  produced  by  cows  passed  as  free  from  udder  tuber- 
culosis by  skillful  veterinarians  especially  on  the  lookout  for  evidences 
of  the  condition. 

How  the  physical  examination  in  this  country  works  out  is  exempli- 
fied by  the  experience  of  Montclair,  N.  J.  (see  Table  25,  p.  49).  For  8 
years  prior  to  the  enforcement  of  the  requirement  that  milk  should  either 
come  from  tuberculin- tested  cows  or  be  pasteurized,  the  herds  supply- 
ing the  town  were  subjected  annually  to  a  physical  examination  by  veteri- 
narians paid  by  the  dairymen.  When  the  tuberculin  test  was  applied 
to  15  of  these  herds  all  but  one  contained  tuberculous  animals,  about 
25  per  cent,  of  the  animals  being  reactors.  It  is  stated  that  at  the  time 
of  testing,  in  only  a  few  cases  could  the  disease  have  been  discovered  by 
physical  examination.  As  autopsies  were  not  performed  on  the  reactors, 
it  is  not  known  how  many  of  the  herds  had  animals  with  open  tuberculosis. 
To  be  at  all  effective,  physical  examinations  must  be  both  frequent  and 
thorough;  consequently  some  dairymen  object  on  the  score  of  cost, 
and  it  is  probably  true  that  in  the  United  States  adequate  physical 
examinations  would  be  more  expensive  than  tuberculin  testing. 

Tuberculin. — Tuberculin,  discovered  by  Koch,  in  1890,  has  been  used 
as  a  diagnostic  agent  for  tuberculosis  in  cattle  since  1891  and  has  been 
adopted  everywhere  for  this  purpose.  It  is  a  liquid,  usually  a  glycerinated 
broth,  that  contains  products  thrown  off  by  tubercle  bacilli  grown  in  it. 
These  products  cause  the  temperature  reaction  that  identifies  a  tubercular 
animal  that  has  been  injected  \\ith  tuberculin.  There  are  no  tubercle 
bacilli  in  tuberculin  because  in  the  process  of  preparation  they  are  killed 
by  heat  and  removed  by  filtration. 

According  to  Moore  the  technique  of  preparing  tuberculin  is  as  follows : 

"The  tubercle  bacteria  are  grown  in  pure  culture  at  about  99.5°F.  on  a  liquid 
medium  consisting  of  beef  tea  containing  peptone  (about  1  per  cent.)  and  glycerin 
(from  5  to  7  per  cent.).  In  some  laboratories  a  little  acid  potassium  phosphate 
is  added.  This  glycerinated,  peptonized  broth  is  put  in  flasks,  usually  in  from 
100  to  250-c.c.  amounts.  After  it  is  sterilized  it  is  inoculated  with  tubercle  bac- 
teria by  transferring  some  of  the  growth  from  a  young  culture  to  the  surface  of 
the  liquid  in  the  flask.  The  bacteria  do  not  grow  in  the  depth  of  the  liquid  but 
form  a  membrane  over  the  surface.  After  the  cultures  have  grown  long  enough, 
from  4  to  10  weeks,  the  flasks  are  placed  in  a  water  bath  and  heated  to  from  121° 
to  149°F.  for  about  2  hr.,  after  which  they  are  boiled.  After  boiling,  these  cul- 
tures are  filtered  through  ordinary  filter  paper  to  remove  the  mass  of  bacteria. 
The  filtrate  is  then  evaporated  over  a  water  bath  to  the  desired  consistency  and 
is  then  filtered  through  a  porcelain  Berkefeld  filter.  In  some  laboratories  it  is 
filtered  through  the  porcelain  filter  before  it  is  concentrated. 

"The  original  Koch  tuberculin  was  evaporated  to  one-tenth  the  volume  of 
the  culture  liquid,  that  is,  100  c.c.  of  the  culture  was  evaporated  to  10  c.c.  and  a 
little  carbolic  acid  (one-half  of  1  per  cent.)  added  to  the  filtrate  to  preserve  it. 
It  is  kept  in  glass-stoppered  bottles. 


40  CITY  MILK  SUPPLY 

"It  has  been  found  that  either  the  human  or  bovine  variety  of  tubercle  bac- 
teria can  be  used  in  the  preparation  of  tuberculin.  Occasionally  a  culture  of 
tubercle  bacteria  is  found  that  will  not  produce  satisfactory  tuberculin.  The 
active  principle  of  tuberculin  is  believed  to  come  from  the  bodies  of  tubercle 
organisms  that  have  become  macerated  in  the  culture  medium." 

The  tuberculin  above  described  is  the  original  tuberculin  of  Koch  and 
is  commonly  marked  T.O.;  he  later  prepared  a  new  tuberculin  from  the 
bodies  of  unheated  tubercle  bacteria  that  is  usually  marked  T.R. 

The  dose  of  tuberculin  is  graduated  to  the  size  of  the  animal.  That 
given  an  adult  animal  of  medium  size  is  0.25  c.c.  of  the  T.O.  That  put  up 
in  the  laboratories  of  this  country  is  so  diluted  that  2  c.c.  is  a  dose. 

There  are  three  different  ways  of  using  tuberculin  to  detect  tubercu- 
losis in  cattle  and  they  are  distinguished  as  (1)  the  subcutaneous  test, 
(2)  the  intradermal  test  or  von  Pirquet  reaction  and  (3)  the  ophthalmic 
test. 

Subcutaneous  Test. — In  the  subcutaneous  test  the  cattle  are  stabled, 
watered  and  fed  in  the  usual  place  and  way.  Since  the  temperature  of 
cattle  varies,  it  is  taken  three  times  at  2-  or  3-hr,  intervals,  previous  to 
injection.  At  8  or  9  p.m.  the  tuberculin  is  administered  beneath  a  fold 
in  the  skin,  commonly  at  the  shoulder.  Seven  hours  after  injection  the 
taking  of  the  rectal  temperatures  of  the  animals  is  commenced  and  obser- 
vations are  taken  thereafter  every  2  or  3  hr.  until  the  twentieth  hour  after 
injection.  The  usual  reaction  consists  of  a  rise  in  temperature  beginning 
about  the  sixth  or  eighth  hour  after  injection  and  continuing  several  hours. 
The  normal  temperature  of  the  cow  is  101  to  102.  5°F.  and  the  tuberculin 
causes  a  rise  of  from  1  to  5°F.  The  interpretation  of  the  thermal  reaction 
requires  experience  and  good  judgment.  Some  testers  regard  a  rise 
of  1.5°  or  2°  above  the  highest  temperature  recorded  prior  to  injection 
as  positive.  Moore,  on  the  basis  of  many  autopsies,  believes  that  a  slight 
rise  may  represent  a  reaction;  that  if  the  curve  is  well-marked,  the  cases 
are  suspicious  when  the  maximum  temperature  ranges  from  103. 5°F. 
down  to  103°  or  even  to  a  few  tenths  of  a  degree  less  and  that  on  slaughter 
40  to  60  per  cent,  of  these  animals  show  tubercular  lesions  but  that  104° 
is  the  minimum  at  which  one  can  make  a  sure  diagnosis. 

The  tuberculin  test  has  certain  limitations.  It  will  not  detect  tuber- 
culosis in  the  prodromal  stage,  or  in  arrested  cases,  or  sometimes  in  very 
advanced  cases  and  it  may  be  vitiated  by  " plugging"  that  is  by  dosing 
the  animal  with  tuberculin  previous  to  the  test.  Also  poor  tuberculin 
or  that  which  is  too  old  is  worthless.  Since  the  test  will  not  pick  out  the 
animals  coming  down  with  the  disease,  nor  those  in  which  it  is  inactive, 
it  is  imperative  to  retest  a  herd  after  6  months  or  at  most  a  year.  Failure 
to  do  so  has  led  to  disastrous  results.  The  fact  that  the  test  does  not 
demonstrate  animals  of  these  classes  has  an  important  bearing  on  the 
slaughter  of  animals  in  tainted  herds  and  on  the  purchase  of  non-reacting 


DISEASES  COMMUNICABLE  IN  MILK  41 

animals  from  infected  herds.  The  value  of  tuberculin  as  a  guide  in  pur- 
chasing is  very  great  but  experience  has  shown  that  when  50  per  cent,  or 
more  of  the  cows  react,  a  considerable  number  of  the  animals  that  do  not 
have  arrested  tuberculosis;  consequently  purchasers  of  non-reactors 
must  retest  at  frequent  intervals.  Failure  to  understand  this  has  led 
to  costly  experiences  on  the  part  of  purchasers  and  to  unjust  charges  of 
dishonesty  against  the  testers. 

A  shortcoming  of  the  tuberculin  test  is  that  it  gives  no  idea  of  the 
severity  of  the  case.  So,  when  animals  are  opened  up,  often  only  an 
inconsequential  lesion  is  found.  In  other  words  the  test  is  regarded  as 
being  too  delicate  by  those  who  would  exclude  only  open  cases  from  their 
herds.  That  the  testing  is  a  searching  one  is  probably  most  fortunate 
and  it  is  likely  that  in  the  end  less  loss  results  from  the  removal  of  animals 
to  which  a  period  of  usefulness  still  remains  than  would  occur  if  the  test 
was  of  such  a  character  as  to  grade  the  cases. 

Of  the  animals  which  give  good  reactions  about  98  per  cent,  show 
lesions  on  slaughter  and  it  is  probable  thorough  examination  of  inaccessible 
parts  would  increase  this  percentage  but  when  the  animals  that  for  rea- 
sons which  have  been  given  do  not  react  are  considered  too,  the  percent- 
age of  accuracy  of  the  test  is  only  about  85  per  cent.,  so  that  the  building 
up  of  a  tuberculosis-free  herd  is  a  matter  not  of  a  year  or  two  but  of  4  to 
8  years. 

Tuberculin  Test  as  a  Criterion  for  Excluding  Milk  from  the  Market— 
All  of  these  imperfections  have  their  bearing  on  the  value  of  the  tubercu- 
lin test  as  a  measure  to  secure  the  public  health  by  shutting  tuberculous 
milk  out  of  the  market.  The  Supreme  Court  of  the  United  States,  the 
Supreme  Court  of  New  Jersey  and  the  courts  of  other  States  have  de- 
clared that  the  proper  authorities  may  require  the  tuberculin  test  to  be 
applied  to  herds  supplying  milk  to  the  communities  within  their  jurisdic- 
tion. Ordinances  making  the  test  compulsory  are  in  force;  they  usually 
make  it  optional  whether  the  dealer  shall  test  his  herds  or  pasteurize 
the  milk.  The  question  arises  whether  such  ordinances  are  wise.  In  the 
first  place  it  should  be  recognized  that  the  enactment  of  such  an  ordinance 
has  a  very  great  educational  effect.  Producers  and  consumers  alike  are 
made  alive  to  the  problem  of  tuberculosis  as  a  whole  and  in  particular  as 
to  the  relationship  of  dairying  thereto.  The  question  is  thoroughly  dis- 
cussed and  usually  all  concerned  are  gainers  from  the  agitation.  The  en- 
forcement of  an  ordinance  helps  the  community  to  which  it  applies  by  re- 
ducing the  number  of  tuberculous  cattle  but  in  this  respect  the  amount  of 
good  accomplished  depends  in  no  small  measure  on  the  spirit  in  which  the 
farmer  meets  the  ordinance.  His  knowledge  of  the  herd  and  a  belief  on 
his  part  that  the  removal  of  reactors  is  for  his  ultimate  benefit  are  all  but 
essential  to  a  thorough  weeding  out  of  diseased  animals.  But  because 
of  faults  inherent  in  the  test  itself,  it  is  highly  improbable  that  even  a 


42  CITY  MILK  SUPPLY 

good  ordinance,  by  the  tuberculin  test  alone,  can  do  more  than  give  a  high 
degree  of  protection  from  the  tuberculous  cow.  Ordinances  that  are 
defective  in  that  they  do  not  provide  for  semiannual  or  at  least  annual 
retests  of  the  herds,  or  that  do  not  require  the  application  of  the  test 
to  replacements  and  additions  to  the  herd  in  the  interval  between  tests, 
or  that  fail  to  provide  for  notification  to  the  proper  authorities  of  what 
final  disposition  of  reactors  is  made,  are  likely  to  fall  far  short  of  giving 
adequate  protection  and  in  some  cases  to  lull  the  consumer  into  a  sense  of 
false  security.  This  is  apt  to  be  almost  certainly  the  case,  if  funds  to 
insure  the  enforcement  of  the  ordinance  are  not  forthcoming.  In  large 
cities  where  the  herds  are  many  and  widely  dispersed  the  expense  of  seeing 
that  such  a  law  is  complied  with  is  very  considerable.  Moreover,  when 
such  ordinances  are  first  put  into  practice  a  concentration  of  losses  is  all 
but  sure  to  fall  upon  the  farmer.  In  small  communities  that  have  re- 
quired the  tuberculin  test  there  has  not  always  ensued  a  rise  in  the  price 
of  milk  but  it  is  claimed  that  should  large  cities  require  it  there  would 
follow  an  increase  of  1  ct.  a  quart.  The  opponents  of  the  tuberculin  test 
also  point  out  that  it  protects  against  one  disease,  tuberculosis,  only 
\\hereas  a  safeguard  against  all  the  diseases  that  may  be  transmitted  by 
milk,  is  furnished  by  the  " holder"  process  of  pasteurization.  Further- 
more it  is  contended  that  inasmuch  as  many  city  dealers  are  already  sup- 
plied with  pasteurizing  machines,  since  it  has  been  found  necessary  to 
pasteurize  milk  shipped  from  distant  points  in  order  to  preserve  it,  there 
will  be  no  necessity  for  increasing  the  price  of  milk  if  compulsory  pas- 
teurization is  substituted  for  the  tuberculin  test. 

There  is  considerable  merit  in  this  argument  but  those  contemplating 
choosing  pasteurization  in  preference  to  the  tuberculin  test  should  not 
for  an  instant  forget  that  pasteurization  is  done  by  machinery  under 
human  direction,  that  both  are  liable  to  failure  and  that  both  need  su- 
pervision. Pasteurizing  machinery  without  automatic  continuous  tem- 
perature-recording devices  is  worthless  while  the  records,  the  machinery 
and  the  finished  product  demand  frequent,  rigid  and  efficient  inspection 
to  keep  the  process  from  degenerating  into  a  fraud. 

The  Intradermal  Test. — The  intradermal  test  is  used  exclusively  in 
Missouri  by  the  State  Veterinarian  in  State  work  but  for  interstate  ship- 
ments the  subcutaneous  test  is  used  because  the  intradermal  test  leaves 
no  record,  and  has  not  been  officially  recognized  by  the  Bureau  of  Animal 
Industry.  The  intradermal  test  is  used  officially  in  the  Territory  of 
Hawaii,  and  in  Delaware  and  California  is  accepted,  if  made  by  an  approved 
veterinarian.  In  the  last-named  State  members  of  the  Experiment 
Station  staff  are  of  the  opinion  that  the  subcutaneous  test  yields  unsatis- 
factory results  on  young  calves,  on  wild  range  cattle  and  on  dairy  stock 
in  the  hot  season  in  some  of  the  interior  valleys.  In  California,  then, 
Ward  and  Baker  and  also  Haring  and  Bell  have  used  the  intradermal 


DISEASES  COMMUNICABLE  IN  MILK  43 

test  extensively.  The  latter  two  authors  have  made  4,926  tests,  including 
retests  on  4,001  head  of  cattle  of  which  1,614  reacted,  the  results  being 
checked  by  1,000  subcutaneous  tests  and  341  autopsies.  They  consider 
that  if  a  5  per  cent,  or  stronger  solution  of  alcoholic  tuberculin  is  used  and 
the  tests  are  performed  by  experienced  operators,  the  results  are  of 
equal  accuracy  to  those  obtained  by  the  subcutaneous  method  and  are 
obtained  with  economy  of  time  and  materials.  They  do  not  recommend 
the  test  for  unskilled  practitioners. 

Injection  is  done  with  a  hypodermic  syringe  having  a  needle  of  25 
or  26  gage  and  a  point  ^{Q  in.  long,  and  is  best  made  into  one  of  the  folds 
of  the  skin  underneath  the  base  of  the  tail.  The  application  of  disinfect- 
ants to  the  point  of  injection  should  be  avoided  for  they  are  likely  to 
produce  swellings  that  may  be  mistaken  for  the  reaction.  A  positive 
result  is  indicated  by  a  thickening  of  the  subcaudal  fold  or  by  the  appear- 
ance at  the  point  of  injection  of  a  sensitive  swelling  varying  in  size  from 
that  of  a  small  pea  to  that  of  an  orange.  Small  indurations  about  the 
size  of  the  head  of  a  parlor  match  frequently  occur  in  normal  non-reacting 
cattle  at  the  point  of  inoculation  but  anything  larger,  that  persists  for  72 
hr.  should  be  considered  a  positive  reaction.  A  recognizable  reaction 
may  be  present  on  the  sixth  hour  after  injection  but  usually  it  is  first 
clear  about  the  twelfth  hour  and  continues  to  increase  in  size  till  the 
forty-eighth  hour.  Delayed  reactions  that  do  not  appear  until  the  nine- 
teenth hour  have  been  noted  and  in  some  instances  early  reactions  dis- 
appeared before  the  forty-eighth  hour.  To  make  certain  of  every  case  two 
observations  must  be  made,  preferably  at  the  thirty-sixth  and  seventy- 
second  hours.  If  only  one  observation  can  be  made,  it  should  be  on  the 
seventy-second  hour.  Haring  and  Bell  found  that  the  injected  cattle  fre- 
quently, but  not  always,  exhibited  a  well-marked  thermal  reaction.  Thus 
in  273  cattle  from  seven  herds,  153  reacted  locally  and  of  these  130  reacted 
thermally,  but  none  reacted  thermally  which  did  not  locally.  It  has 
been  their  experience  that  the  cases  which  fail  to  react  thermally  either  to 
the  intradermal  or  the  subcutaneous  tests  have  usually  been  found  on 
autopsy  to  have  small  encapsulated  lesions.  In  the  course  of  their  work 
they  have  encountered  35  cases  that  showed  a  thermal  reaction  to  the 
subcutaneous  test  but  failed  to  give  a  local  reaction  with  the  intradermal. 
One  of  these  cases  was  autopsied  and  showed  a  few  active  tuberculous 
lesions.  The  failure  of  this  and  the  other  34  cows  to  react  locally  is  ac- 
counted for  on  the  theory  that  a  local  reaction  is  weakened  when  it 
occurs  simultaneously  with  a  thermal  reaction  though  it  is  pointed  out 
that  there  were  many  cases  where  both  reactions  were  well  marked. 

Opinions  as  to  the  relative  accuracy  of  the  subcutaneous  and  intra- 
dermal tests  are  divided,  and  more  data  needed  before  the  question  can  be 
decided.  Those  that  have  used  the  latter  test  extensively  incline  to  the 
belief  that  in  skilled  hands  it  yields  results  of  equal  value  to  those  yielded 


44  CITY  MILK  SUPPLY 

by  other  tests  and  they  regard  it  as  being  more  easy  to  apply  because  the 
necessity  of  taking  temperatures  before  and  after  injection  is  obviated. 
Haring  and  Bell  find  that  like  the  subcutaneous  test  the  intradermal 
test  does  not  always  react  in  advanced  cases  but  think  that  it  will  detect 
more  arrested  cases  and  consider  that  the  results  of  retests  compare  favor- 
ably with  those  obtained  by  the  subcutaneous  method  under  similar  con- 
ditions. Repeated  intradermal  injections  cause  the  animal  to  lose  sensi- 
tiveness to  the  test.  An  alcoholic  tuberculin  should  be  used  in  making 
the  test  and  the  lack  of  a  standard  tuberculin  of  this  sort  is  an  impediment 
it  has  to  meet. 

The  Ophthalmic  Test. — The  ophthalmic  test  was  first  used  on  cattle 
in  1907.  McCampbell  and  White  and  others  find  that  it  has  some  value 
for  diagnosing  tuberculous  cattle.  A  tuberculin  that  does  not  contain 
peptone,  glycerin,  or  carbolic  acid  as  T.O.  tuberculin  does,  must  be  used. 
To  apply  it  the  head  of  the  animal  is  turned  at  an  angle  and  1  to  2  drops 
of  tuberculin  are  dropped  from  a  hypodermic  syringe  right  on  the  eyeball. 
Then  the  closed  eye  is  slightly  massaged  for  several  seconds.  Reactions 
usually  set  in  by  the  eighth  hour  but  may  be  delayed  so  that  observations 
should  be  made  in  the  twelfth,  eighteenth  and  twenty-fourth  hours.  A 
positive  result  is  indicated  by  watering  of  the  eye,  reddening  of  the  con- 
junctiva and  dropsical  swelling  of  the  lid.  A  purulent  exudate  accumu- 
lates later,  at  the  inner  corner  of  the  eye  and  usually  runs  down  into  the 
face.  This  dries  up  and  drops  off  in  a  few  hours.  There  is  no  thermal 
reaction.  The  objection  has  been  raised  that  decision  as  to  whether  or 
not  the  test  is  positive  depends  on  the  opinion  of  the  observer  which  in 
slight  reactions  is  liable  to  error.  Other  objections  are,  that  rain  may  wash 
out  and  obscure  evidence  of  the  reaction ;  long  hay  may  wipe  off  the  exu- 
date and  exposure  to  wind  and  to  bright  sunshine  causes  unsatisfactory 
results.  The  test  is  satisfactory  only  when  the  cattle  can  be  kept  tied 
under  shelter  for  at  least  16  hr.  Haring  and  Bell  with  tuberculin  from 
the  Bureau  of  Animal  Industry  tested  139  cattle  known  to  be  reactors 
and  obtained  positive  results  in  every  case.  They  record  one  case  when 
on  autopsy  a  cow  that  failed  to  react  either  to  the  subcutaneous  or  the 
intradermal  test  but  did  react  to  the  ophthalmic  test,  proved  to  be 
tuberculous. 

One  reaction  probably  inhibits  another  for  a  period  of  6  weeks  to  a 
year  and  is  most  pronounced  in  animals  that  have  not  been  tested  recently 
with  tuberculin;  however,  cattle  that  have  been  so  tested  will  give  the 
reaction  but  with  reduced  intensity. 

Value  of  the  Tuberculin  Test. — In  describing  the  several  methods  of 
using  tuberculin  the  attempt  has  been  made  to  set  forth  plainly  the 
limitations  it  has  as  a  diagnostic  agent  but  it  should  be  clearly  understood 
that  in  spite  of  them  all  it  is  wonderfully  accurate  and  that  when  properly 
used  it  is  a  very  effective  weapon  wherewith  to  fight  this  terrible  scourge 


DISEASES  COMMUNICABLE  IN  MILK 


45 


that  lays  heavy  toll  on  both  man  and  beast.  One  of  the  great  advantages 
it  possesses  is  that  it  has  no  ill  effect  whatever  on  the  health  of  cattle 
that  are  not  affected  with  tuberculosis,  either  when  a  single  injection  is 
given  or  when  it  is  applied  repeatedly  as  in  using  it  in  the  eradication  of 
tuberculosis  from  a  herd. 

Results  of  Tuberculin  Testing. — In  the  United  States  and  Europe 
tuberculin  testing  of  cattle  has  been  widely  used  with  the  result  that 
dairy  cattle  have  been  shown  to  be  extensively  infected  with  tuberculosis. 
Some  of  the  results  obtained  in  this  country  may  be  noticed. 

Tuberculin  Testing  in  Wisconsin. — The  State  of  Wisconsin  has  used 
the  tuberculin  test  more  extensively  and  effectively  than  have  any  of  the 
other  States.  Russell  says  that  it  is  certain  that  two-thirds  of  the 
herds  of  the  State  are  free  from  tuberculosis.  Work  was  begun  in  1893 
with  the  testing  of  the  college  herd  and  has  been  pursued  in  the  State  at 
large  ever  since.  It  is  estimated  that  at  the  present  time  the  tuberculin 
test  has  been  applied  to  from  one-sixth  to  one-fifth  of  the  milch  cows. 
Hastings  says  it  is  certain  that  not  over  5  per  cent,  and  possibly  not  over 
4  per  cent,  of  the  dairy  cattle  are  tubercular  but  he  also  says  that  while 
the  percentage  of  tuberculous  cattle  has  decreased  the  number  of  infected 
herds  has  undoubtedly  increased  and  that  the  great  problem  in  Wiscon- 
sin is  to  prevent  the  introduction  of  tuberculous  animals  into  herds  now 
free  from  the  disease.  The  extent  to  which  the  tuberculin  test  has  been 
applied  may  be  seen  in  Table  19. 

TABLE  19. — TUBERCULIN  TESTING  IN  WISCONSIN,   1893-1912  (HASTINGS) 


Year 

Animals  tested 

Animals  reacting 

Percentage 
reacting 

1893-01 

5,267 

466 

8.8 

1901-02 

425 

84 

19.0 

1902-03 

1,113 

284 

25.5 

1903-04 

914 

171 

18.7 

1904-05 

2,004 

375 

18.7 

1905-06 

l,655(a) 

253 

15.3 

1906-07 

9,718 

1,726 

17.7 

1907-08 

15,816 

1,291 

8.1 

1908-09 

40,993 

2,334 

5.7 

1909-10 

48,181(6) 

2,171 

4.3 

1910-11 

206,631 

6,000(c) 

3.0 

1911-12 

32,272(d) 

1,367 

4.2 

(a)  Slaughter  demonstrations  begun. 

(b)  Indirect  compulsory  legislation. 

(c)  Estimated. 

(d)  Indirect  compulsory  legislation  repealed. 

The  Wisconsin  methods  are  worthy  of  close  study  not  only  because 
they  have  been  tried  on  a  large  scale  but  because  of  the  policy  of  the 
State  in  not  confining  the  testing  with  tuberculin  to  veterinarians  but 


46 


CITY  MILK  SUPPLY 


in  accepting  tests  made  by  cattle  owners  or  by  some  one  that  has  become 
acquainted  with  the  test  by  observation  and  instruction.  Recently, 
certificates  of  competency  to  make  the  test  have  been  granted  by  the  State 
Live  Stock  Sanitary  Board  to  those  passing  its  examinations  and  the  tests 
made  by  such  persons  have  been  accepted  when  it  was  apparent  they 
were  carefully  made,  but  evidence  of  untrustworthy  work  is  penalized 
by  revocation  of  the  permit.  The  work  done  by  professional  and  non- 
professional  testers  has  been  compared  recently  by  Hastings  who  sets 
forth  figures  showing  that  there  is  little  difference  between  them.  It  is 
contended  that  in  granting  the  right  to  test  in  this  way  the  welfare  of 
veterinarians  is  not  materially  injured  for  tuberculin  testing  is  so  time- 
consuming  that  really  competent  men  cannot  afford  to  undertake  it 
extensively  and  on  the  other  hand  this  lifting  of  veterinary  fees  makes 
testing  less  burdensome  to  the  farmers  and  State.  Moreover,  placing  the 
opportunity  to  test  in  the  hands  of  the  farmer  stimulates  his  interest  in 
the  tuberculosis  problem,  gives  him  confidence  in  the  test  and  makes  him 
less  suspicious  that  mercenary  motives  are  behind  legislation  encouraging 
its  application.  Finally,  by  making  the  test  himself  the  farmer  becomes 
familiar  with  the  disease,  a  result  which  it  is  agreed  must  be  attained 
before  real  progress  can  be  made  in  controlling  it. 

In  1916  as  a  result  of  the  efforts  of  the  Commissioner  of  Agriculture, 
the  State  veterinarian  and  the  Live  Stock  Sanitary  Board  of  Wisconsin, 
the  State  has  come  forward  with  a  plan  for  establishing  "accredited  herds" 
from  which  it  is  believed  animals  can  be  shipped  to  other  States  without 
undergoing  the  tuberculin  test. 

A  policy  of  partially  compensating  the  owner  for  his  condemned  stock 
has  enabled  him  to  rid  his  stock  of  the  disease  without  suffering  undue 
financial  loss.  The  burden  of  expense  to  the  State  has  been  greatly 
lessened  by  slaughtering  condemned  animals  and  selling  the  carcasses 
that  pass  federal  meat  inspection. 

The  results  in  Wisconsin  of  inspection  of  carcasses  by  the  federal 
meat  inspection  service  is  appended  in  Table  20. 

TABLE  20. — THE  RESULTS  OF  INSPECTIONS  BY  THE  B.  A.  I.  OF  THE  CARCASSES  OF 
ANIMALS  THAT  REACTED  TO  TUBERCULIN  TESTS  IN  WISCONSIN  (HASTINGS) 


1906-07 

1907-08 

1908-09 

1909-10 

1910-11 

1911-12 

Reacting  animals  
Animals  killed 

1,726 
1,118 

1,291 
1  106 

2,334 
1  816 

2,171 
1,814 

6,000! 
5,034 

1,367 
1,056 

Animals  passed  as  fit  for 
food                      

574 

717 

1,052 

3,866 

751 

Animals  condemned  
Percentage    of    animals 
condemned 

544 

48  0 

389 
35  0 

764 
42  0 

1,168 
23.2 

305 

28.7 

1  Estimated. 


DISEASES  COMMUNICABLE  IN  MILK 


47 


Tuberculin  Testing  in  Hawaii. — In  Hawaii,  in  May,  1910,  the  testing 
of  the  dairies  that  supply  Honolulu  was  begun  and  since,  every  dairy  on 
the  island  of  Oahu,  producing  milk  commercially  and  those  rearing  cattle 
for  sale  have  been  tested  by  the  intradermal  method.  Few  cases  of  tuber- 
culosis were  found  in  range  cattle.  Comparison  of  the  results  in  Table  21 
shows  that  at  every  test  there  were  more  reactors  in  the  city  than  in  the 
country  dairies. 

TABLE  21. — TUBERCULIN  TESTS  IN  THE  TERRITORY  OF  HAWAII,  1910-11-12 
Honolulu  City  Dairies 


Test 

Number 
of  dairies 

One  or  more 
reactors 

Per  cent,  of 
clean  dairies 

Animals 
tested 

Animals 
condemned 

Per  cent,  of 
animals 
diseased 

| 

1 

51 

35 

31.4 

1,404 

439 

31.26 

2 

78 

21 

73.1 

1,778 

160 

8.90 

3 

77 

17 

77.9 

2,056 

111 

5.39 

Island  of  Oahu 


Test 

Number 
of  dairies 

Number  of 
animals 
tested 

Number  of 
animals 
condemned 

Number  of 
suspicious 
reactors 

Number  of 
animals 
passed 

Per  cent,  of 
animals 
condemned 

1 
2 
3 

70 
137 
107 

1,955 
4,162 
5,361 

i  469 
226 
204 

52 
12 

•• 

1,434 
3,924 
5,157 

23.98 
5.80 
3.80 

Total  . 

11,478 

899 

64 

7,515 

7.80 

Tuberculin  Testing  in  North  Carolina. — In  North  Carolina,  testing 
from  1909  to  1911  showed  that  the  native  cows  are  remarkably  free  from 
the  disease;  in  1909  no  reactors  were  found  among  them  and  the  3  years' 
work  indicates  that  only  about  0.1  per  cent,  of  these  cows  were  tubercular. 
In  Table  22  the  high  number  of  reactors  in  1910  occurred  chiefly  in  im- 

TABLE  22. — TUBERCULIN  TESTS  IN  NORTH  CAROLINA,  1909-1911  (CHRISMAN) 


Date 

Number  of                    Number  of 
cattle  tested                    reactors 

Number  of 
suspects 

Percentage 
of  reactors 

1909 

990 

35 

3.53 

1910 

1,997 

136 

32 

6.81 

1911 

3,484 

49 

8 

1.40 

Total  

6,471 

220 

40 

3.40 

ported  cattle  and  in  herds  wherein  infected  cattle  had  been  allowed  to 
stay. 

These  results  are  very  interesting  for  North  Carolina  is  a  State  with 


48 


CITY  MILK  SUPPLY 


no  big  cities;  in  fact,  at  the  time  these  tests  were  made  the  largest  con- 
tained less  than  35,000  inhabitants  so  that  in  no  region  is  production 
forced.  Consequently  there  has  not  been  the  effort  to  develop  large  pro- 
ducing cows  of  pronounced  dairy  type  so  that  there  has  been  little  im- 
portation of  cattle  from  outside  the  State;  the  native  cow  has  sufficed. 
Cows  are  kept  out-of-doors  most  of  the  year.  So,  bringing  in  the  disease 
has  not  been  common  and  the  cows  have  had  a  minimum  of  exposure  in 
infected  barns.  When  the  time  comes  that  extensive  importation  of 
high-bred  stock  becomes  common  there  is  danger,  unless  great  care  is 
exercised,  that  tuberculosis  may  come  with  it,  which  emphasizes  the 
responsibility  breeders  have  in  this  matter  and  which  should  spur  them 
on  to  acquire  tuberculosis-free  herds. 

Tuberculin  Testing  at  Savanah,  Ga. — In  1914-15  Dr.  D.  C.  Gillies, 
for  the  Board  of  Sanitary  Commissioners  of  Savannah,  Georgia,  applied 
the  tuberculin  test  to  the  forty-seven  herds  supplying  the  city  with  milk. 
Dairymen  had  practiced  cross  breeding  freely  so  that  the  resulting  type 
of  cattle,  though  superior  to  the  native  Piney  Woods  stock,  is  inferior 
to  that  stock  improved  by  the  use  of  purebred  bulls.  The  majority  of 
the  herds  were  composed  of  grade  Jerseys,  Guernseys  and  Holsteins 
with  a  few  native  scrubs.  It  was  found  that  seventeen,  or  36  per  cent., 
of  the  herds  were  absolutely  free  from  tuberculosis,  eleven,  or  23  per  cent., 
contained  suspicious  reactors  and  nineteen,  or  40  per  cent.,  contained 
positive  reactors.  In  all,  1,523  animals  were  tested,  of  which  1,347,  or 
88.36  per  cent,  were  non-reactors,  seventy-nine,  or  5.28  per  cent.,  sus- 
picious reactors,  and  ninety-seven,  or  6.36  per  cent.,  positive  reactors. 
Three  herds  furnished  forty-five  suspicious  reactors  (57  per  cent,  of  all 
of  them)  and  sixty-six  positive  reactors  (68  per  cent,  of  all  of  them). 
Dr.  Gillies  believes  that  tuberculosis  was  introduced  years  ago,  and  has 
spread  very  slowly  ever  since.  He  found  the  native  cattle  almost  without 
exception  free  from  tuberculosis  and  that  the  disease  was  not  more 
prevalent  in  one  than  in  any  of  the  other  dairy  breeds.  The  serious 
feature  brought  out  by  the  test  is  that  64  per  cent,  of  the  herds  contained 
either  suspicious  or  positive  reactors. 

Tuberculin  Testing  in  Chester  County,  Pennsylvania. — In  Chester 
County,  Pennsylvania,  the  Supplee  Dairy  Co.  conducted  an  anti-tubercu- 
losis campaign  under  the  direction  of  Lane  with  the  results  that  appear 
in  Table  23. 

TABLE  23. — TUBERCULIN  TESTS  IN  CHESTER  COUNTY,  PENNSYLVANIA  (LANE) 


Date 

Herds 
tested 

Herds 
diseased 

Per  cent,  of 
herds  diseased 

Cows 
tested 

Reactors 

Per  cent,  of 
reactors 

1909 
1910 

86 
51 

41 
11 

47.6 
21.5 

1,063 

585 

197 

27 

18.10 
4.61 

1911 

29 

4 

13.7 

373 

7 

1.87 

DISEASES  COMMUNICABLE  IN  MILK 


49 


Tuberculin  Testing  in  Minnesota. — Some  Minnesota  figures  are  given 
by  Gillie.  In  the  year  ending  Aug.  1,  1908,  25,887  grade  cattle  were 
tested  with  7.7  per  cent,  reactors  and  in  the  same  period  l,329purebreds 
were  tested  with  36.8  per  cent,  reactors.  The  law  requiring  the  test  of 
purebred  cattle  sold  for  breeding  purposes  went  into  effect  Jan.  1, 1910. 
In  the  first  7  months  3,035  such  cattle  were  tested  with  11.2  per  cent, 
reactors  and  from  Aug.  1,  1910,  to  Aug.  1,  1911,  1,717  tests  were  made 
under  the  law  and  of  these  1,214  were  of  cattle  tested  the  year  before; 
only  0.9  per  cent,  of  reactors  were  found  out  of  the  whole  number.  In 
Table  24  are  the  results  that  he  obtained  when  at  the  Minnesota  Experi- 
ment Station. 
TABLE  24. — TUBERCULIN  TESTS  AT  MINNESOTA  EXPERIMENT  STATION  (GILLIE) 


Number 
cattle  tested 

Number 
of  reactors 

Per  cent, 
tuberculous 

Native  

2,839 

223 

7  8 

High  grades 

157 

17 

10  8 

Purebreds                                        .... 

258 

41 

16  6 

Barns  with  fair  ventilation     

1,087 

67 

6  1 

Barns  with  poor  ventilation 

1  210 

201 

16  6 

Tuberculin  Testing  in  Montclair  N.  J. — In  1907  when  Montclair, 
N.  J.,  required  that  either  the  tuberculin  test  be  applied  to  the  herds 
supplying  the  town  or  that  the  milk  be  pasteurized,  17  herds  in  New 
Jersey  were  tested  with  the  results  that  appear  in  Table  25. 

TABLE  25. — TUBERCULIN  TEST  OF  HERDS  SUPPLYING  MONTCLAIR,  N.  J.  (WELLS) 


Herd 

Number 
of  cows 

Per  cent,  of 
reactors 

Cubic  feet  of  air 
space  per  cow 

Square  feet  of  window  area 
per  500  cu.  ft.  of  air 
space 

1 

93 

29.0 

780 

2.7 

2 

69 

18.0 

860 

2.2 

3 

41 

.... 

1,000 

1.5 

4 

35 

455 

3.1 

5 

35 

2.9 

685 

2.8 

6 

28 

53.6 

640 

1.9 

7 

27 

48.1 

410 

4.0 

8 

27 

14.8 

490 

4.1 

9 

23 

34.8 

1,400 

3.1 

10 

14 

50.0 

710 

3.0 

11 

13 

7.7 

475 

2.0 

12 

11 

27.3 

370 

2.8 

13 

10 

.... 

420 

3.0 

14 

9 

44.4 

460 

2.2 

15 

6 

83.3 

390 

3.7 

16 

4 

25.0 

390 

3.7 

17 

3 

33.3 

Part  of  barn  used  as  cow  stable 

50  CITY  MILK  SUPPLY 

These  figures  as  regards  ventilation  in  Tables  24  and  25  are  worthy 
of  remark.  The  higher  percentage  of  reactors  in  the  barns  with  poor 
ventilation  as  noted  in  the  Minnesota  results,  are  such  as  may  be  expected 
but  the  Montclair  figures  show  that  often  stables  with  ample  air  space 
and  window  area  house  badly  infected  herds.  Good  ventilation  and  light- 
ing are  helpful  in  keeping  down  tuberculosis  but  a  cow  with  open  lesions, 
after  all,  is  the  great  big  factor  in  spreading  the  disease. 

The  Lesson  of  Tuberculin  Testing. — Such  is  the  evidence  given  by 
tuberculin  testing;  it  shows  that  bovine  tuberculosis  has  a  firm  hold  wher- 
ever dairying  has  become  an  important  industry.  In  some  places  the 
disease  has  been  but  recently  introduced;  many  herds  in  the  United 
States  are  free  from  it.  The  problem  is  to  keep  them  so  and  to  eradicate 
the  plague  from  herds  that  are  already  affected.  The  task  is  stupendous 
but  it  must  be  performed  because  infected  milk  and  dairy  products 
menace  the  young  and  because  the  disease  cuts  deeply  into  the  profits 
of  the  producer  and  greatly  increases  the  cost  of  living  to  the  consumer. 
The  emphasis  that  has  been  laid  on  the  public  health  aspect  of  the  prob- 
lem has  probably  tended  to  make  breeders  and  dairymen  feel  that  the 
principal  way  in  which  they  were  concerned  was  in  preventing  measures, 
designed  to  debar  the  marketing  of  infected  dairy  produce,  from  being 
drastic.  On  the  other  hand,  the  consumer  has  no  doubt  often  felt  that 
he  was  being  imposed  on  in  being  compelled  to  pay  the  farmer  for  slaught- 
ered diseased  stock  even  though  it  was  condemned  by  the  representative 
of  the  consumer  and  in  his  interest.  Both  viewpoints  are  wrong  and  those 
who  are  endeavoring  to  improve  the  situation  must  lose  no  opportunity 
to  drive  home  the  fact  that  both  producers  and  consumers  are  supporting 
an  industry  that  is  oppressively  and  outrageously  taxed  by  the  ravages 
of  a  communicable  disease.  The  tax  will  be  levied  whether  efforts  to 
control  the  disease  are  made  or  not.  By  letting  the  disease  run,  the  in- 
convenience of  paying  to  uproot  it,  is  avoided  but  collection  is  made  in 
the  end,  in  the  form  of  feeding  animals  that  are  too  sick  to  yield  milk  in 
paying  quantity,  of  lessened  fecundity  of  the  herds,  of  loss  of  valuable 
stock,  of  suspicion  that  is  engendered  of  purebred  stock,  of  loss  of  meat 
that  is  condemned  as  food  and  of  bills  that  are  pai4  the  physician  and 
surgeon  for  care  of  tubercular  patients,  and  the  undertaker  for  burying 
them.  The  welfare  of  all  demands  that  the  disease  be  attacked,  not  in  a 
desultory  fashion  but  in  a  carefully  thought  out  campaign,  planned  to 
be  fought  out  on  the  lines  laid  down  for  10  years  or  more  if  necessary. 
As  yet  no  fully  satisfactory  plan  for  dealing  with  the  menace  has  been 
evolved  anywhere.  The  methods  that  are  actually  in  use  may  be  profit- 
ably considered. 

Control  of  Tuberculosis  by  Immunization. — In  the  first  place,  it  should 
be  noted  that  attempts  have  been  made  to  immunize  dairy  animals  but 


DISEASES  COMMUNICABLE  IN  MILK  51 

as  yet  these  efforts  have  not  developed  beyond  the  stage  where  they  are 
of  more  than  scientific  interest. 

Control  by  Tuberculin  Testing. — The  plan  that  is  probably  most 
familiar  to  Americans  is  that  of  testing  animals  with  tuberculin  and 
destroying  the  reactors.  If  retests  are  made,  there  is  little  doubt  that 
herds  would  be  enventually  cleaned  up  but  the  system  is  too  expensive 
to  be  generally  adopted.  To  apply  it  to  a  whole  State  would  require  an 
army  of  testers  and  the  value  of  property  destroyed  would  be  so  great  as 
to  be  prohibitive.  Moreover,  a  severe  shortage  of  milk  would  very  likely 
result  so  that  this  method  can  be  applied  only  in  a  limited  way.  Had  it 
been  adopted  before  tuberculosis  had  obtained  a  firm  hold  of  American 
stock,  it  no  doubt  would  have  achieved  success,  but  now  it  is  too  harsh. 

The  Manchester  Method  of  Control. — In  England,  the  Manchester 
system  is  in  use;  it  is  based  on  the  unsound  hypothesis  that  tubercle 
bacteria  get  into  milk  only  through  udder  lesions  or  at  least  principally 
that  way.  The  law  on  which  the  system  is  based  authorizes  the  proper 
officials  to  collect  milk  samples  and  to  visit  dairies  both  within  and  with- 
out the  city  proper.  The  milk  of  all  dealers  is  submitted  at  regular  in- 
tervals to  microscopical  examination  and  is  also  tested  by  injection  into 
guinea-pigs.  In  case  the  mixed  milk  proves  to  be  infected  with  tuber- 
culosis germs  the  herds  are  visited  and  the  animals  examined  physically  by 
a  veterinarian.  Animals  with  tuberculosis  of  the  udder  are  removed  from 
the  herd  but  the  law  does  not  provide  for  their  destruction.  Milk  from 
the  animals  removed  must  not  be  sold  for  human  consumption  nor  can 
the  cow  be  kept  with  other  cows  in  milk.  There  is  nothing  to  prevent 
their  being  kept  with  dry  stock  nor  with  calves  and  disinfection  after 
removal  of  the  diseased  animals  is  not  required.  It  is  easy  to  see  that  the 
law  is  a  compromise  and  was  enacted  in  the  belief  that  it  would  reduce  the 
amount  of  tuberculous  milk  on  sale.  It  has  been  held,  that  by  removing 
the  cows  with  udder  lesions,  the  law  would  lessen  the  amount  of  open 
tuberculosis  in  the  herds  and  gradually  effect  their  betterment.  The 
actual  result  has  been  that  in  the  first  few  years  after  enactment  bad 
conditions  were  improved  but  so  far  as  the  milk  is  concerned  it  has  been 
found  that  after  10  years  in  Manchester  the  tuberculous  samples  dropped 
down  to  6  per  cent,  and  in  Sheffield  to  9  per  cent,  and  stayed  there. 
Statistics  show  that  in  neither  city  during  the  same  period  had  there  been 
any  percentage  reduction  of  udder  tuberculosis. 

The  Ostertag  Method  of  Control. — The  Ostertag  method  is  based 
on  the  theory  that  it  is  the  open  cases  of  tuberculosis  that  spread  the 
disease  and  that  all  but  a  few  of  these  are  detectable  by  frequent  and 
thorough  physical  examinations  of  the  herds.  As  tuberculin  does  not 
distinguish  open  from  closed  cases  it  is  not  used.  The  herd  is  examined 
by  a  veterinary  inspector  after  which  there  is  a  bacteriological  examina- 
tion of  the  milk.  If  tuberculosis  is  found  in  the  milk  or  if  animals  whose 


52  CITY  MILK  SUPPLY 

appearance  arouses  suspicion  of  the  disease  are  discovered,  reexamination 
of  the  animals  is  made.  Those  exhibiting  clinical  symptoms  are  isolated 
or  slaughtered.  Calves  are  removed  promptly  after  birth  and  kept 
separate  some  months  when  they  are  placed  with  other  cattle.  During 
the  period  of  separation  the  calves  are  fed  on  the  milk  of  sound  animals 
or  on  the  pasteurized  milk  of  infected  ones.  The  method  is  undoubtedly 
helpful  but  is  objected  to  in  the  United  States  because  it  amounts  to 
treating  the  whole  herd  as  though  it  were  tuberculous  and  because  of 
the  expense  attached  to  the  frequent  veterinary  examinations  which  are 
the  vital  part  of  the  scheme  of  treatment.  Many  regard  the  method  as 
palliative  rather  than  curative. 

The  Bang  Method  of  Control. — The  Bang  system  is  more  thorough 
than  those  that  have  been  described.  The  entire  herd  is  treated  with 
tuberculin,  the  reactors  are  separated  from  the  sound  cattle  and  the  prem- 
ises disinfected.  Doubtful  cases  are  kept  under  observation  and  if  not 
separated  from  the  healthy  animals  in  the  first  place  are  so  whenever  there 
is  reason  to  believe  them  diseased. 

The  tubercular  animals  are  preferably  kept  in  a  separate  building  on  a 
part  of  the  farm  away  from  the  sound  stock  but  where  necessity  compels, 
they  may  be  kept  in  a  part  of  the  barn  containing  the  others,  if  they  are 
walled  off  so  completely  that  there  is  no  possible  communication  between 
the  two.  The  sick  and  the  well  animals  are  pastured  separately.  Owing 
to  the  ease  with  which  manure  and  other  infectious  material  may  be  trans- 
ferred from  one  herd  to  another  separate  attendants  for  the  two  parts  of 
the  herd  should  be  provided  if  it  can  be  afforded.  The  reacting  and  non- 
reacting  cattle  should  not  have  the  same  watering  troughs. 

Cows  that  have  tuberculosis  of  the  udder  are  slaughtered.  Calves 
that  are  dropped  by  tubercular  mothers  are  taken  away  before  they  have 
a  chance  to  suck  and  are  raised  on  the  milk  of  sound  cows  or  on  milk  of 
the  tubercular  stock  pasteurized  at  176°F.  Experience  has  taught  that 
calves  are,  with  but  rare  exceptions,  born  free  from  tuberculosis.  The 
rearing  of  calves  from  advanced  cases  is  not  encouraged  for  the  few  cases 
of  intra-uterine  infection  that  do  occur  most  often  arise  in  the  progeny  of 
such  cows.  The  whole  stock  including  the  calves  is  retested  every  half 
year,  reactors  removed  and  necessary  disinfection  attended  to.  Ulti- 
mately a  sound  herd  is  built  up,  and  the  diseased  stock  out  of  which  it 
came  is  slaughtered. 

The  advantages  of  the  system  are:  (1)  It  is  efficient,  for  by  its  use  a 
tuberculosis-free  herd  can  be  obtained  in  from  1  to  3  years  though  some- 
times 6  to  8  years  are  required  in  a  badly  infected  herd.  (2)  The  initial 
expense  is  not  great.  (3)  It  does  not  disturb  trade.  (4)  Owners  and 
herdsmen  obtain  thorough  knowledge  of  the  disease,  an  acquisition  of 
inestimable  value  to  them.  The  disadvantages  are:  (1)  Extra  labor  is 
required.  (2)  Great  vigilance  is  exacted  for  any  laxity  will  undo  the  work 


DISEASES  COMMUNICABLE  IN  MILK  53 

of  years.  (3)  Perseverance  is  demanded  of  the  owner,  for  final  success  can 
be  won  by  only  persistent  effort  in  the  face  of  discouraging  setbacks. 

In  Denmark  where  the  Bang  system  was  developed  there  have  been 
formed  by  the  farmers  associations  which  enable  the  members  to  bring 
their  tubercular  stock  into  a  single  herd  and  therefrom  raise  up  sound 
animals  at  a  minimum  of  trouble  and  expense.  The  formation  of  similar 
societies  has  been  proposed  in  the  United  States  but  actually,  none  seem 
to  have  been  created.  In  some  States  there  has  been  some  discussion  of 
the  suggestion  that  the  State  assist  the  farmers  in  the  formation  and  care 
of  such  herds,  with  the  object  of  encouraging  dairymen  to  establish  herds 
of  tuberculosis-free  animals  and  of  conserving  breeding  animals  of  valu- 
able dairy  strains  that  are  now  butchered  after  reacting  to  tuberculin. 
The  proposition  has  some  merit  and  no  doubt  in  competent  hands  would 
prove  satisfactory  but  if  conducted  as  a  political  sinecure  it  would  do  a 
deal  of  harm. 

The  Birmingham  Method  of  Control. — Savage  has  described  a  mode  of 
maintaining  the  Bang  system  in  Birmingham,  England,  that  might  be 
used  in  small  cities  in  the  United  States.  The  city  supplies  farmers  the 
tuberculin  and  veterinary  assistance  necessary  for  testing  their  cows  twice 
a  year.  The  farmer  disinfects  the  stables  and  separates  the  diseased  and 
healthy  animals.  Tuberculosis-free  cows  are  marked  and  those  having 
tuberculous  udders  are  sold  for  slaughter.  The  city  gives  quarterly 
certificates  to  owners  of  tuberculosis-free  herds  and  keeps  a  public  list  of 
their  farms.  In  this  way  several  sound  herds  have  been  built  up  and 
more  are  on  the  way. 

Use  of  the  Bang  Method  in  the  United  States. — -In  the  United  States 
and  Canada  private  owners  have  built  up  tuberculosis-free  herds  and 
so  have  several  of  the  experiment  stations,  by  the  Bang  method.  The 
Wisconsin  Stations,  the  first  to  use  it,  began  in  1896  with  16  reactors 
and  18  well  cows.  In  February,  1899,  the  herd  had  27  well  animals 
bred  from  reactors.  The  New  York  Station  in  1901  had  13  healthy 
animals  and  17  tuberculous.  It  lost  four  healthy  animals  by  fire  and  only 
a  few  heifer  calves  were  born  but  in  1905  it  had  a  herd  of  30  sound  and 
six  tubercular  animals.  The  latter  were  slaughtered.  The  experience 
in  building  up  the  herd  at  the  Illinois  Station  has  been  told  by  Hayden. 
In  Table  26  appears  a  statement  of  the  females  in  the  herd,  the  number 
tested  and  the  number  of  reactors. 

There  were  several  reasons  for  not  testing  the  entire  herd  at  different 
times  but  usually  the  principal  one  was  that  many  of  the  animals  were 
regarded  as  too  young  to  test. 

Despite  great  loss,  and  with  the  addition  of  a  few  calves  from  another 
herd,  the  number  of  females  increased  from  55  in  1907  to  91  clean  females 
in  1912.  In  the  period  19  females  were  purchased  and  32  non-reactors 
sold.  The  herd  was  well-seeded  with  tuberculosis  previous  to  1908  and 


54 


CITY  MILK  SUPPLY 


the  harvest  was  reaped  in  May  of  that  year  when  32.6  per  cent,  of  the 
cows  reacted.  Of  47  mature  cows  in  1906  only  three  remained  in  the 
herd  after  1909  and  only  five  of  those  that  went  out  did  so  for  other  causes 
than  tuberculosis  which  shows  that  when  a  herd  of  mature  animals 
becomes  badly  diseased  it  is  probably  best  to  consider  the  entire  herd 
affected  and  to  treat  it  accordingly.  In  the  breeding  herd  170  different 
females  were  tested  and  50  or  about  30  per  cent,  reacted. 

TABLE   26. — TUBERCULIN  TESTING  AT  ILLINOIS  EXPERIMENT  STATION,   1906-1912 

(HAYDEN) 


Year 

Season 

Number  of  females 
in  herd 

Number  tested 

Number  of 
reactors 

1906 

May 

44 

34 

13 

December 

15 

10(o) 

1907 

June 

55 

5 

2 

1908 

June 

67 

50 

26 

Fall 

56(6) 

36 

3 

1909 

Fall 

78 

67 

4 

1910 

Spring 

72 

57 

1 

Fall 

77 

72 

0 

1911 

Spring 

88 

70 

1 

Fall 

96 

90 

1 

1912 

March 

95 

81 

4 

(a)  Five  of  the  reactors  had  reacted  previously. 
(6)  Seven  animals  acquired  by  purchase. 

From  May,  1906  to  December,  1911,  five  mature  bulls  and  32  young 
ones  ranging  from  6  months  to  2  years  of  age  were  tested;  three  reacted, 
of  these,  one  that  reacted  was  fed  on  sterilized  milk  like  the  other  calves 
but  still  developed  the  disease  either  because  this  milk  was  not  always 
properly  heated  or  for  some  other  reason.  Besides  these,  26  bull  calves 
under  6  months  of  age  from  sound  cows  were  sold. 

In  Table  27  are  shown  the  results  obtained  from  19  of  the  purebred 
cows  that  were  quarantined  in  1908  and  from  four  others  that  were  quar- 
antined later. 

The  quarantined  herd  was  kept  in  existence  for  about  2  years  at  a 
cost  of  $60  a  head  a  year,  or  a  total  cost  of  $2,700  for  the  2  years.  During 
that  time  the  gross  returns  were  approximately  $4,436  making  a  net  re- 
turn of  $1,736.  The  cost  was  probably  greater  than  it  would  be  for  an 
ordinary  herd. 

The  Disinfection  of  Stables. — The  disinfection  of  the  stable  is  a 
matter  which  must  be  carefully  attended  to  on  the  removal  from  the  herd 
of  animals  suffering  from  tuberculosis  or  other  infectious  diseases.  The 
first  step  is  to  clean  up  thoroughly,  being  careful  to  scrape  the  manure 
from  the  floor  and  walls  and  to  sweep  the  stable  clean  so  that  the  germi- 


DISEASES  COMMUNICABLE  IN  MILK 


55 


TABLE  27. — TUBERCULIN  TESTING  OF  23  Cows  AT  THE  UNIVERSITY  OF  ILLINOIS 
EXPERIMENT  STATION,   1908-1910  (HAYDEN) 


Herd 

num- 
ber 

1908 

1909 

1910 

Post- 
mortem 

Value 
before 
tubercular 

Received 
for 
carcasses 

Received 
for 
milk 

Value 
of 
progeny 

Total 

10 

T  + 

T  4- 

+  Cond. 

$100 

$  6.75 

$  84.71 

$  91.46 

16 

T  + 

T  + 

T  4- 

+ 

200 

43.67 

163.71 

$100 

307.38 

33 
36 

T  + 

T  4- 

T  + 
T  4- 

4. 

100 
150 

67.10 

107  .  96 
137.13 

75 
200 

250.06 
337.13 

39 
49 

T  + 
T  + 

T  + 
T  4- 

100 
200 

27.77 

113.44 
98.77 

80 
100 

221.21 
198.77 

51 
52 

T  +  T  + 
T  4- 

T  4- 

T  + 

+  Cond. 
4-  Cond. 

100 

75 

7.58 
5.00 

127.88 
98.25 

85 

220.46 
103.25 

54 

T  + 

T  + 

100 

25.50 

62.74 



88.24 

56 

T  + 

T  + 

4- 

150 

78.61 

5 

83.61 

57 

T  + 

T  + 

4- 

+  Cond. 

75 

6.75 

76.41 



83.16 

58 

T  +  T  + 

T  + 

+  Cond. 

100 

7.00 

77.87 

75 

159.87 

59 

T  +  T  + 

T  + 

4- 

100 

57.91 

111.38 

70 

239  .  29 

60 

T  4- 

T  + 

4- 

125 

44.59 

127.14 

90 

261.73 

64 

T  + 

T  + 

4- 

150 

30.40 

130.08 

180 

340.48 

66 

T  + 

T  + 

+  Cond. 

150 

7.96 

111.15 

100 

219.11 

67 

T  + 

T  + 

? 

150 

33.12 

115.74 

150 

298.86 

71 

T  + 

.... 

T  4- 

4- 

150 

34.43 

139.63 

180 

354.06 

72 
41 

T  + 

T  + 
T  + 

4- 

150 
175 

43.67 
43.61 

25.91 
128.99 

80 
100 

149.58 
272.60 

29 

T  4-  ? 

' 

175 

25.50 

57.05 

82.55 

42 

T  +  T  - 

_j_ 

175 

12.50 

23.75 

36.25 

Heifers 

T  4-  T  — 

100 

37.56 

3,050 

568.37 

2,198.30 

1,670 

4,436.67 

T  +  Means  reaction. 
T  —  Means  no  reaction. 
Cond.  Means  condemned. 

cide  can  easily  come  into  contact  with  the  surfaces  to  be  disinfected. 
It  is  very  difficult  to  disinfect  worn  and  decayed  woodwork;  so  rotten 
floors  and  mangers  should  be  torn  out  and  burned.  The  earth  from  dirt 
floors  should  be  removed  to  a  depth  of  at  least  4  in.  so  as  to  get  rid  of  the 
fecal  discharges  it  has  absorbed.  The  next  step  is  to  apply  the  germicide. 
There  are  many  disinfectants  from  which  to  choose  and  in  making  a  selec- 
tion several  points  should  be  borne  in  mind,  namely:  (1)  their  efficiency, 
(2)  their  non-poisonous  qualities,  (3)  their  freedom  from  irritating  action 
on  man  and  beast  and  from  odors  that  will  cling  to  the  building  and  be 
absorbed  by  the  milk  making  it  unsaleable,  and  (4)  their  cost.  As  a  rule 
proprietary  disinfectants  should  be  avoided  because  if  they  have  any  value 
at  all  it  depends  on  some  of  the  well-known  germicides  that  costs  less 
under  its  own  name  than  when  masquerading  under  a  fancy  title  be- 
stowed by  some  manufacturer.  The  common  disinfectants  are  mercuric 
chloride  or  corrosive  sublimate,  formalin,  chloride  of  lime  or  bleaching 
powder,  carbolic  acid  or  phenol,  cresol,  compound  solution  of  cresol  or 
liquor  cresolis  compositus,  crude  carbolic  acid  and  sulphur. 

Tuberculosis  in  Swine. — The  swine  in  most  cases  contract  the  disease 


56  CITY  MILK  SUPPLY 

from  eating  cattle  droppings  for  the  grain  they  contain,  or  from  being  fed 
on  skim-milk  from  tuberculous  cows.  They  may  also  become  infected 
with  tuberculosis  germs  of  the  avian  type  from  the  droppings  of  fowls. 
In  the  latter  case  the  disease  is  usually  of  a  local  character  while  the 
bovine  bacilli  give  rise  to  a  generalized  infection.  Wherever  slaughter 
houses  keep  record  of  the  points  from  which  the  animals  come  and  as  to 
whether  they  are  tuberculous  or  not,  there  is  afforded  evidence  that  may 
be  utilized  in  tracing  up  diseased  herds  and  in  mapping  regions  that  are  so 
generally  infected  that  the  animals  coming  therefrom  may  be  expected  to 
be  tuberculous.  In  this  connection  it  should  be  said  that  range  animals 
are  commonly  pretty  free  from  the  disease,  but  of  late  years  a  tendency 
for  it  to  increase  in  this  sort  of  stock  has  been  noted.  Thus  reports  of 
meat  inspectors  in  San  Francisco  and  Los  Angeles  indicate  that  the  pro- 
portion of  cattle  from  certain  ranges  which  are  affected  with  tuberculo- 
sis has  increased  from  1  to  5  per  cent,  in  the  last  five  years. 

Viability  of  B.  Tuberculosis  in  Butter  and  Ice  Cream. — Dairy  products 
are  to  some  extent  infected  with  the  germs  of  bovine  tuberculosis.  Cream, 
whether  raised  by  gravity  or  separated,  carries  bacteria  with  it  so  that  it 
is  natural  for  both  butter  and  ice  cream  made  from  the  milk  of  tubercular 
cows  to  contain  tubercle  bacilli  since  neither  the  salting  of  the  butter 
nor  the  freezing  destroy  the  microbes. 

Briscoe  and  MacNeal  have  compiled  a  list  of  39  investigations  of  the 
butter  of  24  European  and  one  American  city;  out  of  1,233  samples  163 
or  13.2  per  cent,  were  infected  with  the  germs  of  tuberculosis.  They  found 
that  two  out  of  six  samples  of  butter  from  Urbana,  111.,  examined,  carried 
the  bacilli.  By  experiment  they  found  that  tuberculosis  germs  sur- 
vive in  a  virile  condition  for  a  much  longer  period  than  the  butter  is  usu- 
ally held  in  cold  storage.  This  is  in  line  with  Mohler's  statement  that 
tubercle  bacilli  retain  their  virulence  in  butter  made  in  the  usual  way 
and  stored  under  ordinary  market  conditions  until  time  of  sale.  It  should 
be  mentioned  that  butter  made  from  carefully  pasteurized  cream  does  not 
carry  tuberculosis  germs. 

Viability  of  B.  Tuberculosis  in  Oleomargarine. — In  the  usual  way  of 
making  oleomargarine  in  the  United  States  the  fat  used  is  comminuted  at 
not  over  122°F.  for  1%  hr.  Then  sour  milk  is  added  and  the  whole  mass 
thoroughly  mixed ;  dairy  butter  is  next  added  and  a  certain  proportion  of 
vegetable  oils.  Next,  enough  more  oils  are  added  to  lower  the  tempera- 
ture to  that  of  dairy  butter.  Therefore,  opportunity  is  afforded  the  prod- 
uct to  be  infected  in  three  ways,  viz. :  (1)  by  the  fat  from  the  cattle,  for 
tubercle  bacilli  will  withstand  a  temperature  of  122°F.  for  some  hours; 
(2)  from  the  butter  and  sour  milk  that  is  added;  and  (3)  in  the  process  of 
manufacture  it  may  be  contaminated  by  tuberculosis  germs  of  human 
origin.  Briscoe  and  MacNeal  enumerate  seven  investigations  of  oleomar- 


DISEASES  COMMUNICABLE  IN  MILK  57 

garine  in  six  European  cities  and  in  nine  of  the  samples  from  two  different 
cities  tubercle  bacilli  were  found. 

Viability  of  B.  Tuberculosis  in  Cheese. — Whether  or  not  cheese  contains 
tubercle  bacilli  depends  on  the  time  that  elapses  in  the  ripening  process. 
In  Switzerland  it  was  demonstrated  that  in  Emmenthal  cheese  the  tuber- 
cle bacilli  died  between  the  thirty-third  and  fortieth  day  of  ripening  and 
as  the  process  is  continued  considerably  longer  before  the  cheese  is  mar- 
keted there  is  little  cause  to  be  apprehensive  that  the  bacilli  survive.  The 
bacilli  of  tuberculosis  live  much  longer  in  cheese  made  by  the  cheddar 
process.  In  Switzerland  it  was  found  that  during  ripening  they  lived 
104,  but  not  111  days.  In  Maryland,  Mohler  and  Doane,  in  this  variety 
of  cheese,  demonstrated  tuberculosis  germs  after  122  days,  a  period  that 
approaches  the  limit  of  that  it  is  sometimes  allowed  to  ripen.  Altogether 
it  seems  unlikely  that  cheese  often  carries  the  germs  of  tuberculosis. 
Of  course  cottage  cheese  and  any  other  that  is  eaten  soon  after  it  is  made 
is  likely  to  be  infected  with  the  bacilli  if  it  comes  from  the  milk  of  tuber- 
cular cows. 

Need  of  a  Comprehensive  Tuberculosis  Policy. — It  is  apparent  that 
the  problem  of  bovine  tuberculosis  is  very  urgent. 

Foot-and-mouth  Disease. — This  highly  contagious  disease  chiefly 
affects  ruminants  and  swine.  It  gets  its  name  from  the  fact  that  it  is 
characterized  by  vesicular  eruptions  on  the  mucous  membrane  of  the 
mouth  and  on  the  skin  between  the  toes  of  the  affected  animal.  The 
causative  organism  has  never  been  isolated  but  it  is  held  to  be  a  filterable 
virus.  Aphthous  fever,  as  the  malady  is  sometimes  called,  is  common  in 
Europe  but  has  never  gained  permanent  foothold  in  this  country  because 
whenever  it  has  appeared,  the  affected  herds  have  been  promptly  de- 
stroyed by  slaughter.  The  disease  is  communicable  to  man,  children 
being  more  susceptible  to  it  than  adults.  It  is  spread  by  contact,  through 
the  vesicles,  nasal  discharges,  saliva,  feces  and  milk.  Most  often  it  is 
acquired  from  ingesting  infected  milk  or  its  products,  but  it  may  be  also, 
through  abrasions  in  the  skin,  in  handling  or  slaughtering  the  sick  ani- 
mals. The  incubation  period  is  generally  3  or  4  days  and  the  progress  of 
the  disease  has  been  described  as  causing  fever,  vomiting,  sometimes  pain- 
ful swallowing,  heat  and  dryness  of  the  mouth,  followed  by  an  eruption  of 
vesicles  on  the  mucous  membrane  of  the  mouth  and  rarely  on  the  fingers. 
The  vesicles  are  about  the  size  of  a  pea,  soon  rupture  and  heal  slowly. 
Patients  usually  recover;  the  few  deaths  are  mostly  among  children. 
The  disease  is  uncommon  in  the  United  States  but  a  few  cases  were  re- 
ported in  humans  in  the  epizootics  of  1870,  1902,  1908  and  1914. 

Anthrax. — This  disease  is  caused  by  Bact.  anthracis.  Man  is  rarely 
infected  through  the  alimentary  tract  but  is  sometimes.  That  he  might 
be,  seems  to  have  been  known  for  a  long  time  for  in  1599  during  an  anthrax 
epidemic  in  Venice  the  sale  of  meats,  milk,  butter  and  fresh  cheese  was 


58  CITY  MILK  SUPPLY 

prohibited  under  penalty  of  dqath.  The  bacterium  has  been  recovered 
from  the  milk  of  cows  suffering  from  the  disease  but  there  seems  to  be  only 
very  slight  danger  of  men  taking  the  disease  from  milk,  for  the  flow  is  sup- 
pressed or  if  delivered  is  altered  in  character  and  also  the  cow  dies  a  few 
hours  after  the  beginning  of  the  attack.  Ernst  states  that  the  dangers 
of  infection  through  the  ingestion  of  raw  milk  containing  the  bacteria  is 
slight  because  anthrax  bacteria  are  digested  by  the  gastric  juice  but  that 
it  does  not  destroy  the  spores.  Consequently  infection  of  the  milk  by 
spores  from  the  manure  of  diseased  animals  or  of  healthy  ones  that  have 
eaten  food  containing  anthrax  spores,  and  also  by  spores  derived  from 
dust  and  straw  offers  possibilities  of  dangers.  That  infections  from  milk 
do  occur  is  known.  Kober  cites  the  case  of  the  daughter  of  a  plantation 
owner  at  Barbados  in  1795,  who  one  morning  drank  most  of  the  milk  of  a 
cow  suffering  from  anthrax  and  who  4  days  later  showed  symptoms  of  the 
disease  which  were  followed  by  the  development  of  a  carbuncle  on  her 
right  arm.  Ernst  instances  the  case  of  a  typhoid  fever  patient  who  after 
drinking  1.5  liters  of  milk  from  a  cow  with  malignant  pustule  of  the  udder, 
became  infected  with  intestinal  anthrax. 

In  a  dairy  district  supplying  Chicago,  from  June  to  August,  1910,  an 
outbreak  of  anthrax  occurred,  which  threatened  the  milk  supply  of  the 
city.  The  epidemic  lasted  about  60  days.  Twenty  farms  were  involved 
and  500  cows  exposed  of  which  number  87  died  of  the  disease.  The  out- 
break spread  rapidly  and  required  vigorous  efforts  to  check  it.  Inspect- 
ors from  Chicago  were  put  in  the  district  and  quarantined  every  farm  on 
which  the  disease  was  actually  present  or  was  suspected  of  harboring  it. 
All  milk  on  these  farms  was  destroyed.  This  vigorous  campaign  kept 
the  milk  out  of  Chicago.  In  the  course  of  the  epidemic  one  farmer  died 
of  anthrax  but  apparently  did  not  contract  the  disease  from  milk. 

Cowpox. — This  disease  is  believed  to  be  smallpox  modified  by  passage 
through  the  cow.  It  is  well  known  that  milkers  and  others,  who  are 
brought  into  close  contact  with  cows  having  the  disease,  break  out  with 
it.  Indeed,  it  was  observation  of  this  fact  and  that  milkers  who  had 
contracted  it  seldom  had  smallpox  that  led  Jenner  to  propose  vaccination. 
It  is  within  the  bounds  of  possibility  that  infants  and  others  might  get 
cowpox  from  drinking  milk  containing  pustular  matter  abraded  from  the 
udder  in  milking  but  it  is  not  known  that  any  ever  did.  However,  boards 
of  health  properly  exclude  from  the  market,  the  milk  of  cows  suffering 
with  cowpox. 

Rabies. — That  anyone  should  milk  a  rabid  animal  is  most  improbable 
but  as  it  has  been  reported  that  the  disease  has  been  transmitted  to  the 
young  in  the  milk,  calves  of  diseased  animals  should  be  prevented  from 
sucking. 

Ernst  cites  a  case  reported  by  Bardach  of  a  nursing  infant  remaining 


DISEASES  COMMUNICABLE  IN  MILK  59 

well,  although  it  fed  on  the  milk  of  a  woman  suffering  from  rabies  until 
one  day  before  her  death. 

Milk-sickness. — In  pioneer  days,  in  restricted  areas  in  the  Central 
West,  this  disease  worked  such  havoc  to  stock  and  man  that  it  was  regarded 
as  a  serious  menace  and  rewards  were  offered  by  legislatures,  for  the  dis- 
covery of  its  cause.  It  appeared  about  1800  and  continued  of  importance 
till  1860  when  it  all  but  vanished.  The  sickness  has  never  been  known 
east  of  the  Alleghenies  nor  outside  of  the  United  States.  Cultivation  of 
the  soil  favors  the  disappearance  of  the  disease.  The  observation  was 
early  made  that  man  might  be  made  sick  from  using  the  milk,  butter  or 
meat  of  animals  having  the  disease  known  as  the  trembles  or  slows  and 
that  probably  the  ailment  of  man  was  identical  with  that  of  the  animals. 

In  cattle  the  first  indication  of  the  sickness  is  dullness,  followed  by 
violent  trembling  and  great  weakness  which  increases  during  the  succeed- 
ing day  until  the  animal  becomes  paralyzed  and  usually  dies  though  old 
reports  indicate  that  some  of  the  animals  recovered  but  were  greatly 
impaired  by  the  disease.  In  man  the  disease  develops  marked  weariness, 
retching  and  insatiable  thirst.  Respiration  is  labored,  peristalsis  ceases, 
the  temperature  becomes  subnormal  and  the  patient  -apathetic.  Paral- 
ysis gradually  ensues  and  death  takes  place  quietly  without  rigor  mortis. 

The  early  settlers  had  no  idea  of  the  cause  of  the  sickness  in  animals, 
but  found  that  they  contracted  it,  if  allowed  to  feed  in  certain  localities. 
So  they  expected  to  find  that  some  plant  or  mineral  poisoned  the  stock. 
Early  students  of  the  illness  made  lists  of  plants  and  minerals  of  the 
areas  that  were  known  to  be  dangerous.  Jordan  and  Harris  solved  the 
mystery  in  ]  907  when  the  appearance  of  the  disease  in  New  Mexico  gave 
them  an  opportunity  to  apply  bacteriological  methods  in  studying  it. 
They  isolated  a  bacillus  from  the  intestinal  contents  of  affected  animals 
and  man,  that  was  sometimes  found  in  pure  culture  in  the  internal  organs 
of  fatal  cases  and  that,  fed  to  dogs  and  calves,  reproduced  in  part,  at  least, 
typical  symptoms  of  the  slows.  They  call  the  organism  B.  lac'imorbi. 

Malta  Fever. — Malta  fever  is  caused  by  the  Micrococcus  melitensis 
which  was  discovered  by  Bruce  in  1887,  but  knowledge  as  to  the  mode 
of  transmission  of  the  disease  was  worked  out  from  1905  to  1907  by  the 
British  Commission  for  the  investigation  of  Mediterranean  fever.  The 
disease  is  prevalent  in  the  Mediterranean  Basin  and  in  the  United  States, 
in  the  goat-raising  States  to  which  it  has  been  imported  in  blooded  animals 
from  Europe  and  Asia  Minor.  As  yet,  it  seems  to  have  been  found  only 
in  Texas,  Arizona,  and  New  Mexico,  but  it  may  reasonably  be  suspected 
that  careful  diagnostical  work  will  demonstrate  the  disease  in  California 
and  Oregon.  The  British  investigations  were  undertaken  because  of 
the  prevalence  of  Malta  fever  in  the  island  of  Malta.  It  was  found  that 
the  specific  micrococcus  is  contained  in  the  milk  und  urine  of  apparently 
healthy  goats  so  that  there  is  ample  opportunity  for  man  to  infect  himself 


60  CITY  MILK  SUPPLY 

by  drinking  goat's  milk  and  less  readily  by  inhaling  infected  dust  and  by 
eating  food  that  has  been  exposed  to  such  dust.  In  this  connection  it 
should  be  noted  that  while  the  micrococci  succumb  readily  to  heat 
and  disinfectants  they  manifest  considerable  resistance  to  drying.  In 
certain  parts  of  Texas  the  indications  are  that  dust  transmission  of  the 
disease  is  important.  Possibly  the  disease  may  be  spread  by  flies. 

Malta  fever  is  characterized  by  profuse  perspiration,  constipation, 
frequent  relapses  often  accompanied  by  rheumatic  or  neuralgic  pains 
and  sometimes  by  swellings  of  the  joints.  The  disease  is  long  drawn  out 
and  has  a  mortality  rate  of  about  3  per  cent.  In  Texas  it  has  been  known 
as  Rio  Grande  or  goat  fever  and  is  sometimes  confused  with  typhoid 
fever  though  practitioners  often  recognize  that  the  disease  is  not  true 
typhoid.  Isolation  of  the  micrococcus  and  agglutination  tests  serve  to 
distinguish  the  diseases.  In  the  United  States,  it  is  apparently  in  the 
kidding  season  that  the  disease  is  most  often  contracted,  for  the  reason 
that  it  is  at  this  time  that  the  milk  flow  is  heaviest  and  that  at  this  time, 
also,  the  rancher's  whole  family  live  with  the  goats.  Precaution  should 
be  taken  to  boil  the  milk  and  to  locate  the  pens  so  that  there  is  a  mini- 
mum of  dust  exposure  to  the  family. 

Contagious  Abortion. — The  bacillus  of  contagious  abortion  is  common 
in  market  milk  and  the  fact  that  it  was  pathogenic  for  cattle  roused  the 
suspicion  that  it  might  in  some  way  be  for  man.  Shroeder  at  one  time 
believed  that  Bad.  abortus  might  be  responsible  for  tonsillar  troubles  and 
adenoids  in  children  but  neither  he  and  Colton  nor  Mohler  and  Traum 
were  able  to  prove  the  theory  by  testing  a  large  number  of  diseased  tonsils 
and  many  samples  of  adenoid  tissue  excised  from  children. 

Larson  and  Sedgwick  in  1913  called  attention  to  the  fact  that  the 
blood  serum  of  children  using  milk  from  cattle  infected  with  contagious 
abortion,  often  contains  antibodies  against  Bact.  abortus.  In  a  series 
of  425  children  whose  blood  was  tested  to  either  or  both  agglutination 
and  complement  fixation  73,  or  17  per  cent,  gave  a  positive  reaction.  Cer- 
tain groups  of  these  children  gave  a  much  higher  percentage  of  positive 
reactions;  thus  the  children  of  one  institution  gave  over  40  percent,  and  of 
another  as  high  as  48  per  cent.  Children  that  were  fed  on  the  milk  of 
herds  known  to  be  free  from  the  disease  did  not  give  the  reaction  while 
those  fed  on  ordinary  market  milk  did.  The  authors  state  that  while  it 
could  not  be  determined  whether  the  presence  of  these  antibodies  in  the 
blood  of  children  is  the  result  of  an  infection  or  of  antibody  absorption 
through  the  digestive  tract  they  incline  to  the  former  interpretation  be- 
cause they  consider  it  improbable  that  antibodies  could  be  excreted  in 
quantities  sufficient  to  give  a  positive  complement  fixation  test. 

Cooledge  found  by  experiment  that  Bact.  abortus  antibodies  may  be 
present  in  milk  in  great  concentration  and  that  they  may  be  made  to 
appear  in  the  blood  serum  of  adults  by  feeding  them  milk  naturally 


DISEASES  COMMUNICABLE  IN  MILK  61 

infected  with  Bad.  abortus.  He  believes  that  antibodies  appearing  in  this 
way  indicate  passive  immunity  due  to  the  absorption  in  the  larger  intes- 
tine of  antibodies  from  the  infected  milk  and  that  there  is  no  proof  that 
Bad.  abortus  is  pathogenic  to  man.. 

Sore  Teats. — Udder-borne  infections  have  been  imputed  to  teat  sores 
and  Savage  notes  two  instances  in  which  diphtheria  germs  have  been  iso- 
lated from  the  ulcerated  teats  of  cows  belonging  to  herds  supplying  dairies 
that  were  implicated  in  outbreaks  of  the  disease.  *  It  was  not  believed  that 
diphtheria  germs  caused  the  sores  but  that  the  diphtheria  was  an  added 
infection  for  which  the  milkers  were  responsible.  Whether  organisms 
that  cause  these  sores  are  ever  dangerous  is  not  known;  they  may  be  so, 
but  at  present  they  are  regarded  lightly. 

Gastro -enteritis  Caused  by  Udder  Infection. — Hoist  in  1894,  reported 
four  different  outbreaks  of  gastro- enteritis  in  Christiania,  Norway,  that 
were  traced  to  the  consumption  of  the  milk  of  cows  affected  with  strepto- 
coccic  mastitis.  Lameris  also,  concluded  that  diarrhea  may  be  caused 
by  the  use  of  milk  of  cows  suffering  from  streptococcial  infection  of  the 
udder.  Others  also,  have  reported  outbreaks  caused  in  this  way.  Gron- 
ing  and  Hoist  have  instanced  cases  where  the  milk  had  been  boiled  before 
those  who  partook  of  it  were  made  ill.  So  there  is  the  question  whether 
the  boiling  was  not  thorough  enough  to  kill  the  organisms  or  whether 
the  bacteria  elaborated  poisons  that  were  not  destroyed  by  the  heat 
applied. 

In  the  United  States  one  of  the  most  definite  outbreaks  of  this  sort 
occurred  in  Gibbsborough  and  Berlin,  N.  J.,  on  Oct.  15,  1915,  on  the  milk 
route  of  dealer  A  who  was  supplied  by  three  dairymen  each  of  whose  milk 
he  bottled  separately.  On  the  day  in  question  A  put  out  82  qt.  of  milk 
in  all,  13  qt.  of  D's,  11  of  C's  and  58  of  B's.  Sixty  pint  bottles  which  were 
all  that  A  delivered  that  day,  except  a  few  of  D's  milk  that  certainly  did 
not  cause  illness,  were  filled  with  B's  milk  as  were  28  quart  bottles.  Only 
13  other  quart  bottles  were  put  out  by  A  that  day.  The  bulk  of  the  milk 
was  produced  and  bottled  on  the  14th.  In  the  two  towns  there  were  55 
cases  of  gastro-enteritis,  simulating  ptomaine  poisoning  and  giving  one  or 
more  of  the  symptoms  of  vomiting,  dizziness,  headache,  prostration,  pains 
in  the  stomach  and  diarrhea.  All  of  the  victims  used  dealer  A's  milk  and 
among  them  were  some  of  his  own  family.  Because  in  23  of  the  families 
that  were  attacked,  pint  bottles  of  dairyman  B's  were  used  and  because  his 
milk  was  in  all  probability  used  in  eight  invaded  homes  that  took  milk  in 
quart  bottles  suspicion  was  fastened  on  his  dairy.  Investigation  disclosed 
that  two  of  B's  own  children  who  used  the  milk  were  stricken  with  pains 
in  the  stomach  and  vomiting  and  that  the  herd  had  been  tended  by  a  hired 
man  but  that  when  the  sickness  broke  B  examined  the  herd  and  on  finding 
a  cow  with  a  bruised  udder  and  injured  teat,  discharged  the  man  and  dis- 
carded the  milk  of  the  cow.  Veterinary  examination  indicated  that  the 


62  CITY  MILK  SUPPLY 

cow  was  tuberculous  and  showed  her  to  be  suffering  from  an  extensive 
and  acute  inflammation  of  one  quarter  of  the  udder  and  that  the  milk 
from  this  quarter  was  contaminated  with  pus  and  blood.  Microscopical 
examination  of  the  milk  showed  numerous  polymorphonuclear  leukocytes 
and  many  streptococci  in  fairly  long  chains  of  16  to  10  elements.  At- 
tempts to  isolate  the  streptococci  failed.  In  the  opinion  of  the  veteri- 
narian the  cases  of  illness  reported  on  the  milk  route  of  A  were  due  to  the 
infected  milk  of  B's  cow  for  the  following  reasons: 

1.  All  the  55  cases  of  illness  in  31  homes  occurred  on  A's  milk  route. 

2.  In  23  of  these  31  homes,  those  who  become  ill  consumed  milk  from 
bottles  known  to  have  been  filled  with  the  product  of  B's  dairy. 

3.  The  distribution  of  28  quart  bottles  filled  with  milk  from  B's  dairy 
will  account  for  illness  in  eight  homes  where  the  milk  from  quart  bottles 
was  consumed.     Only  13  quart  bottles  filled  with  milk  from  other  dairies 
were  distributed  on  the  date  in  question. 

4.  All  cases  of  illness  were  of  similar  character  and  occurred  on  the 
same  date. . 

5.  No  more  cases  of  illness  occurred  after  milk  from  the  infected  udder 
was  discarded. 

6.  Cases  of  illness  occurred  in  both  the  families  of  A,  the  distributor, 
and  B,  the  dairyman. 

7.  No  other  common  food  supply  to  cause  the  illness  in  31  homes  was 
found. 

Out  of  a  total  of  82  qt.  of  milk  distributed  by  dealer  A  on  the  15th, 
74  pt.  of  milk  and  41  qt.  of  milk  were  accounted  for  and  it  was  found  that 
364  people  ate  at  the  tables  where  this  milk  was  served,  323  of  whom 
drank  the  milk  or  used  it  in  coffee  or  on  cereals.  Of  this  number  268 
remained  well  and  55  or  20.5  per  cent,  took  sick. 

The  repeated  acute  attacks  of  gastro-enteritis  that  occurred  among 
the  residents  at,  and  visitors  to  a  farm  in  the  Phillipine  Islands  over  a 
period  of  3  years  were  shown  by  Barber  to  be  due  to  a  toxin  elaborated 
by  a  white  staphylococcus  that  occurred  in  almost  pure  culture  in  the 
udder  of  a  cow,  that  was  apparently  in  good  health  at  all  times  except  for 
a  single  attack  of  garget  that  occurred  after  the  cases  of  gastro-enteritis 
had  begun.  The  fresh  milk  was  harmless  and  the  toxin  was  produced 
only  after  the  milk  had  stood  some  hours  at  room  temperature.  Persons 
using  the  milk  continuously  apparently  developed  some  tolerance  to  the 
toxin.  Two  children  used  the  milk  regularly  but  never  had  attacks. 
Adults  had  light  attacks  and  in  one  or  two  instances  developed  cases  of 
chronic  intestinal  trouble.  Visitors  to  the  farm  and  Filippino  employees 
had  the  worst  cases.  On  discontinuance  of  the  milk  of  the  infected  cow 
all  trouble  ceased. 

Gastro-enteritis  Caused  by  Fecal  Contamination. — Some  diarrheal 
infections  may  be  derived  from  perfectly  healthy  animals  that  are  handled 


DISEASES  COMMUNICABLE  IN  MILK  63 

in  an  uncleanly  manner  thus  affording  opportunity  for  the  milk  to  re- 
ceive heavy  fecal  contamination.  The  diarrhea  of  infants  may  be  due 
to  various  causes ;  it  may  be  incited  from  improper  food  without  definite 
connection  with  bacteria  but  Kendall  has  pointed  out  that  the  acute 
summer  diarrheas  that  show  "  prostration  and  fever  associated  with 
mucus,  pus  and  sometimes  even  blood"  in  the  movements  may  be  caused 
by  various  bacteria.  He  found  that  on  the  Boston  Floating  Hospital,  in 
"one  year  the  dysentery  bacillus  was  the  dominant  type  met  with;  the  sec- 
ond year  streptococci  were  conspicuous;  the  third  summer  was  note- 
worthy because  of  the  great  number  of  cases  in  which  the  gas  bacillus  was 
the  predominant  organism  encountered;  while  in  the  fourth  summer  an 
entirely  different  organism,  somewhat  resembling  B.  mucosus,  made  its 
appearance."  This  bacterial  diarrhea  is  believed  to  be  in  part  derived 
from  milk  that  shows  high  bacterial  count,  the  tender  gastro-intestinal 
membrane  being  overwhelmed  by  mere  numbers  of  the  germs.  Also,  it 
cannot  be  denied  that  there  may  be  in  the  feces  of  healthy  animals  germs 
which  if  they  get  into  the  milk  may  attain  considerable  development 
therein  and  become  noxious  to  consumers,  particularly  to  babies.  This 
is  believed  to  be  the  case  at  times  with  yeast  cells  and  B.  subtilis  and 
even  with  the  common  B.  coli.  The  milk  of  scouring  cows  is  thought  by 
some  to  be  more  likely  than  that  of  well  ones  to  give  trouble  in  this  way 
and  in  herds  whose  milk  is  used  especially  for  infant  feeding  the  milk  of 
such  cows  is  withheld.  Another  organism,  Bad.  welchii  which  is  often 
called  the  gas  bacillus  and  by  English  writers  B.  enteritidis  sporogenes  and 
which  is  also  known  by  other  names,  was  found  by  Klein  in  the  stools 
of  the  victims  of  an  outbreak  of  diarrhea  and  Andrewes  studied  three 
outbreaks  of  a  mild  type  which  occurred  in  St.  Bartholomew's  Hospital, 
London,  England,  in  which  this  organism  was  present  in  the  stools  of  the 
patients  and  in  the  milk  which  was  incriminated  as  the  cause  of  the  out- 
break. In  one  of  these  epidemics  146  persons  were  taken  ill  in  one  night. 
The  pathogenic  power  of  the  organism  is  variable ;  certain  strains  accord- 
ing to  Theobald  Smith  form  toxins  if  they  are  grown  in  media  con- 
taining minimal  amounts  of  sugar.  In  the  vast  majority  of  cases  Bad. 
welchii  seems  to  be  a  saprophyte  living  upon  the  intestinal  contents  and 
not  a  true  invading  organism.  This  microbe  is  an  anaerobe  and  is 
rather  widely  distributed  in  nature,  occurring  in  dust,  the  excrement  of 
man,  cows  and  the  higher  animals;  in  many  samples  of  market  milk  and 
in  large  numbers  in  sewage.  It  is  not  a  normal  inhabitant  of  the  intesti- 
nal tracts  of  nurslings.  Kendall  and  Smith  examined  for  Bad.  welchii, 
293  stools,  some  of  which  were  normal  and  some  were  not.  In  271  the 
result  was  negative,  showing  that  the  organism  is  rare  in  the  stools  of 
infants  and  young  children.  Eight  of  the  stools  showed  the  germs  present 
but  not  in  quantity  to  warrant  their  being  considered  significant.  This 
result  was  not  unexpected  for  the  discharges  of  older  children  on  a  mixed 


64 


CITY  MILK  SUPPLY 


diet  and  those  of  a  few  infants  sometimes  contain  the  organism.  In  14 
cases  Bad.  welchii  was  found  in  sufficient  numbers  to  sanction  the  belief 
that  it  was  the  exciting  cause  of  the  diarrhea.  That  fecally  contaminated 
milk  offers  a  possible  source  of  infection  with  this  organism  must  be 
admitted. 

Simonds  says  that  there  are  some  reasons  for  believing  that  Bad, 
welchii  of  human  origin  may  be  virulent  and  that  of  bovine  not  so. 

Unclean  Milk  at  the  U.  S.  Naval  Academy. — There  is  evidence  that 
impure  milk  is  the  cause  of  indefinite  intestinal  disorders  among  adults 
and  that  the  substitution  of  a  pure  supply  for  an  impure  one  is  attended 
with  good  results.  The  experience  at  the  U.  S.  Naval  Academy  at  An- 
napolis, Md.,  is  a  case  in  point.  A  few  years  ago  Paymaster  Samuel 
Bryan,  U.S.N.,  who  was  charged  with  provisioning  the  Naval  Academy  at 
Annapolis,  Md.,  requested  the  Bureau  of  Animal  Industry  to  test  for 
tuberculosis  some  of  the  herds  from  which  milk  was  being  obtained  by 
contract.  The  demonstration  of  the  disease  and  the  presence  of  an  undue 

TABLE  28. — THE  EFFECT  ON  THE  ATTENDANCE  OF  INTRODUCING  A  PURE  MILK  SUPPLY 
TO  THE  U.  S.  NAVAL  ACADEMY 


Year 

Average  attend- 
ance at  the 
Academy 

Number  of  sick 
days  due  to  intes- 
tinal disorders 

Cases  of  typhoid 
fever 

October   1910-Sept  30  1911 

759 

1,598 

29 

October,  1911-Sept.  30,  1912  
October,  1912-Sept.  30,  1913  

860 

875 

296 
253 

Typhoid     pro- 
phylactic used 

October,  1913-Sept.  30,  1914  
October   1914-Sept  30  1915 

914 
922 

228 
270 

on  brigade. 

TABLE  29. — REDUCTION    OF    INTESTINAL    DISORDERS    CONSEQUENT   UPON    INTRO- 
DUCING A  PURE  MILK  SUPPLY  TO  THE  U.  S.  NAVAL  ACADEMY 


Year 

Sick  days  due  to  intestinal  disorders 

Remarks 

October 

November 

1910 

184 

840 

Milk    secured     by    contract 

only. 

1911 

53 

60 

In  every  month,  save  two, 

milk  wholly  from  Academy. 

1912 

0 

19 

Milk   wholly  from  Academy 

herd. 

1913 

22 

6 

Milk   wholly  from  Academy 

herd. 

1914 

23 

25 

Milk  wholly  from  Academy 

herd. 

1915 

16 

16 

Milk   wholly  from  Academy 

herd. 

DISEASES  COMMUNICABLE  IN  MILK  65 

amount  of  typhoid  fever  and  minor  intestinal  disorders  among  the  mid- 
shipmen and  the  difficulty  of  getting  contract  milk  that  was  produced 
under  fit  sanitary  conditions  led  to  the  establishment  of  a  dairy  with  a 
herd  of  90  cows  selected  by  the  Bureau  of  Animal  Industry.  A  new  barn 
was  built  and  a  determined  and  successful  effort  was  made  to  keep  flies 
out  of  it. 

The  Academy  supply  was  first  served  the  midshipmen  on  October  1, 
1911,  but  a  part  of  the  contract  supply  was  continued  in  use  for  2  months. 
The  young  men  are  in  prime  physical  condition  and  their  diet  is  con- 
trolled, yet  a  remarkable  reduction  in  absences  from  classes  was  obtained 
when  they  were  given  the  milk  from  the  Academy  herd.  No  other  change 
in  the  food  was  made  and  the  authorities  attribute  the  improvement 
shown  in  Tables  28  and  29  solely  to  the  improved  milk  supply. 

Diseases  of  Class  II. — The  second  class  of  diseases  transmitted  in 
milk,  is  made  up  of  certain  infections  derived  from  man  and  comprises 
typhoid  fever,  paratyphoid  fever,  Asiatic  cholera,  diphtheria,  scarlet  fever, 
and  septic  sore  throat.  Of  all  the  diseases  of  this  class  it  may  be  said 
with  assurance  that  the  recorded  number  of  milk-borne  epidemics  is 
decidedly  less  than  actually  have  occurred.  This  is  partly  because  many 
epidemics  are  never  investigated,  and  partly  because  health  officers  and 
others  often  do  not  regard  epidemics  which  they  have  throttled  to  be  of 
sufficient  general  interest  to  write  up.  In  other  cases  local  pride  and  busi- 
ness interests  may  keep  outbreaks  quiet. 

In  very  few  instances  has  the  specific  disease  germ  been  isolated  from 
the  suspected  milk.  This  is  usually  because  the  game  is  not  worth  the 
candle;  in  most  cases  the  bacteriological  technique  is  tedious  and  uncer- 
tain but  of  at  least  equal  moment  is  the  fact  that  whereas  the  milk  sup- 
ply is  not  apt  to  remain  infected  for  more  than  a  short  time  the  incuba- 
tion period  of  the  disease  may  last  several  days  or  even  2  weeks  so  that 
the  disease  germs  disappear  from  the  milk'  before  the  contagion  breaks 
out.  Then,  in  the  case  of  scarlet  fever,  the  specific  organism  is  unknown. 
So,  epidemiological  methods  are  chiefly  relied  on  to  detect  sources  of 
infection  and  to  nip  budding  epidemics. 

Typhoid  Fever. — Typhoid  fever  is  a  communicable  disease  that  is 
spread  by  direct  contact  and  by  infected  water,  milk,  oysters  and  other 
foods,  and  by  flies.  The  relative  importance  of  these  several  modes  of 
dissemination  varies  in  different  places  but  everywhere  that  it  is  consumed 
raw,  milk  is  more  than  likely  to  be  an  important  factor  in  spreading  the 
disease.  In  some  localities  it  may  take  first  place  as  a  disseminator; 
this  is  apt  to  be  so  where  other  causes  have  been  largely  eliminated. 
Thus  in  1907  Harrington  stated  that  in  Massachusetts,  where  pure  water 
supplies  are  the  rule,  for  the  2  years  past,  14  out  of  18  outbreaks  of  ty- 
phoid fever  were  due  to  milk. 

Milk  is  a  very  common  source  of  typhoid  infection;  Trask  and  a  few 


66  CITY  MILK  SUPPLY 

workers  mentioned  by  him  have  collected  from  literature  somewhat  over 
500  epidemics  of  typhoid  fever  that  were  milk-borne.  In  the  United 
States  apparently  the  first  recorded  outbreak  of  typhoid  fever  that  was 
attributed  to  milk  was  that  at  Allegheny  City,  Pa.,  in  1882  but  it  was 
not  till  about  1889  that  the  reporting  of  such  epidemics  became  common. 
Trask's  own  list  is  composed  of  179  epidemics  of  which  107  were  in  the 
United  States,  43  in  Great  Britain,  three  in  Continental  Europe,  three  in 
Australia,  one  in  New  Zealand  and  two  in  Canada.  There  are  several 
ways  of  accounting  for  the  preponderance  of  cases  in  this  country  but  the 
fact  that  raw  milk  is  more  generally  used  here  than  abroad  is  outstanding. 

Typhoid  fever  may  be  transmitted  in  milk  products  as  well  as  in  whole 
milk.  In  Kober's  list  of  epidemics  there  are  three  that  occurred  in 
Ireland  during  1892-96,  that  were  conveyed  by  skim-milk  returned  to 
farms  from  creameries.  In  some  cases  whole  milk  was  infected  on  the  farm 
of  patrons  and  was  mixed  with  that  of  others  at  the  creamery  while  in 
other  instances  the  milk  was  infected  by  creamery  employees.  The  group 
of  cases  is  interesting  for  in  these  days  when  the  attempt  is  being  made 
to  persuade  legislatures  to  protect  cattle  and  hogs  from  foot-and-mouth 
disease  and  tuberculosis  by  enacting  laws  requiring  the  pasteurization 
of  skim-milk  and  whey  at  creameries  and  cheese  factories  before  its 
return  to  the  farm,  additional  force  is  lent  the  argument  by  pointing  out 
that  such  laws  would  also  protect  human  beings  from  contagion.  In  this 
country  Sedgwick  in  1894  traced  an  epidemic  in  Marlboro,  Mass.,  to  skim- 
milk  from  a  creamery. 

The  experiments  of  Mitchell  show  that  B.  typhosus  can  be  recovered 
from  inoculated  frozen  cream  after  3  weeks  or  more.  Ice  cream  has  been 
held  responsible  for  typhoid  epidemics ;  four  have  been  recorded  in  Great 
Britian  and  two  in  the  United  States.  The  first  of  those  in  this  country 
was  reported  by  Horton  from  Montclair,  N.  J.,  in  1894. 

Butter  is  recognized  as  a  possible  medium  of  transmission  of  typhoid 
fever  but  there  seem  to  be  no  recorded  epidemics  due  to  it.  Bruck 
infected  milk  with  B.  typhosus,  separated  it  and  was  able  to  find  the  or- 
ganism 10  days  thereafter  in  both  the  buttermilk  and  cream.  In  butter 
made  from  this  cream  he  recovered  the  bacillus  after  27  days.  Other 
workers  have  obtained  similar  results.  Typhoid  fever  germs  certainly 
live  long  enough  in  butter  for  them  to  reach  the  consumer  in  a  virulent 
condition  so  that  if  butter  is  made  from  infected  milk  or  cream,  typhoid 
cases  may  be  expected  among  those  who  eat  it.  However,  there  are  several 
reasons  that  diminish  the  probability  of  butter  becoming  a  distributor  of 
typhoid  fever.  In  the  first  place,  it  should  be  recognized  that  the  process 
of  manufacture  plays  a  part.  Butter  may  be  made  from  pasteurized 
cream,  from  sweet  cream  or  from  sour  cream,  it  may  be  salted  or  unsalted. 
Butter  from  pasteurized  cream  is  perfectly  safe  if  the  pasteurization  has 
been  properly  done  and  the  cream  is  not  subsequently  infected.  Unsalted 


DISEASES  COMMUNICABLE  IN  MILK  67 

butter  from  sweet  cream  is  most  likely  to  be  dangerous  for  it  receives  the 
benefit  of  no  inhibitory  principles  other  than  those  inherent  in  itself, 
namely,  that  it  is  a  solid  medium  containing  comparatively  little  mois- 
ture. Salt  is  mildly  antagonistic  to  microbial  life,  but  the  salting  that 
butter  receives  is  never  heavy. 

Effect  of  Lactic  Acid  on  Disease  Germs. — The  greatest  protection 
is  in  the  acids,  and  possibly  other  products,  formed  by  the  lactic  acid 
bacteria  in  souring  the  cream.  Many  experiments  have  been  made  to 
measure  the  germicidal  effect  that  souring  cream  has  on  the  typhoid 
bacillus.  Some  observers  have  found  no  such  action  but  the  latest 
experiments  indicate  that  it  is  very  considerable,  that  it  reduces  the  num- 
ber of  typhoid  bacilli  but  cannot  be  relied  upon  to  kill  them  all. 

Krumwiede  and  Noble  found  that  the  typhoid  bacillus  is  gradually 
killed  in  sour  cream  by  the  acids  produced,  the  rate  of  destruction  being 
proportional  to  the  degree  of  acidity  and  the  number  of  typhoid  bacilli 
present.  With  moderate  contamination  the  typhoid  bacilli  are  killed 
in  about  4  days,  but  with  heavy  contamination,  or  when  initial  multipli- 
cation has  taken  place,  it  may  take  longer. 

Heinemann  found  that  "some  acid  tolerant  cells  of  B.  coli  may  sur- 
vive the  presence  of  0.6  per  cent,  lactic  acid  in  milk."  B.  dysenterice, 
B.  typhosus,  B.  paratyphosus  0,  Sp.  cholerce,  and  B.  diphtheria  in  the 
experiments  were  destroyed  in  the  presence  of  0.45  per  cent,  lactic  acid. 
It  is  possible  that  strains  of  these  bacteria  exist  which  are  able  to  resist 
a  greater  amount  of  lactic  acid.  Acid  tolerant  strains  of  B.  coli,  B. 
dysenterice,  B.  typhosus  and  B.  paratyphosus  |8,  may  multiply  in  the  pres- 
ence of  quantities  of  lactic  acid  which  are  destructive  to  the  majority  of 
cells.  The  smaller  the  initial  amount  of  lactic  acid,  the  more  likely  is 
the  growth  of  acid-tolerant  strains  to  occur.  Therefore,  the  slower  milk 
sours  the  greater  is  the  danger  of  pathogenic  bacteria  surviving. 

The  growth  of  the  test  bacteria  is  influenced  to  a  marked  degree  by 
the  amount  of  acid  present.  Up  to  a  fairly  definite  amount  of  acid  there 
is  an  increase  in  numbers,  followed  by  a  decrease,  which  becomes  more 
pronounced  as  the  amount  of  acid  increases.  The  amount  of  acid  may 
increase  owing  to  the  liberation  of  enzymes,  after  the  number  of  bacteria 
has  commenced  to  decrease. 

Possible  Infection  of  Butter  in  Wrapping. — There  is  opportunity  for 
butter  to  be  infected  by  those  who  work  it  after  it  is  made.  It  is  com- 
monly shipped  from  creameries  to  the  large  cities  in  tubs,  and  is  there  put 
up  in  prints  or  packages  for  sale.  This  necessitates  more  handling  and  by 
another  set  of  employees.  Perhaps  this  last  process  is  not  the  least  im- 
portant, for  the  butter  reaches  the  public  soon  after  being  wrapped, 
whereas  at  other  stages  in  its  progress  to  the  consumer,  it  is  held  in  cold 
storage  and  opportunity  is  given  the  germs  to  die  out.  However,  many 
prints  are  wrapped  by  machine  and  are  handled  little  in  the  process. 


68  CITY  MILK  SUPPLY 

Buttermilk  is  commonly  sold  soon  after  it  is  made,  so  that  while  it 
undoubtedly  is  to  a  considerable  degree  antagonistic  to  typhoid  germs,  the 
possibility  of  its  containing  them  must  be  conceded.  Fraenkel  and 
Kister  believed  that  the  unusual  amount  of  typhoid  fever  at  Hamburg, 
Germany,  in  1897  was  in  part  due  to  infected  buttermilk.  Heinemann 
found  that  acids  other  than  lactic  acid  are  frequently  present  in  butter- 
milk. Since  these  acids  may  not  be  as  strongly  germicidal  as  lactic 
acid,  it  should  be  looked  upon  with  suspicion,  especially  if  heavily  pol- 
luted, unless  prepared  from  pasteurized  milk.  Still,  the  chance  of  but- 
termilk becoming  the  carrier  of  infection  is  much  less  than  of  raw  sweet 
milk.  "The  presence  of  saprophytic  bacteria  in  buttermilk  may  have 
some  influence  on  pathogenic  bacteria.  Whether  this  influence  is  favor- 
able or  otherwise  is  difficult  to  determine  by  present  bacteriological 
methods." 

Typhoid  bacilli  have  been  shown  to  be  recoverable  from  artificially 
infected  cheese  after  some  3  weeks.  The  period  would  probably  vary 
with  the  type  of  cheese.  Unless  cheese  should  be  made  of  infected  milk 
and  eaten  soon  afterward  as  cottage  cheese  and  some  others  might  be, 
there  is  little  likelihood  of  contracting  typhoid  from  this  source. 

Paratyphoid  Fever. — Paratyphoid  fever  is  spread  in  the  same  way 
that  typhoid  fever  is.  Dr.  F.  G.  Curtis  reported  an  outbreak  of  the  dis- 
ease in  Newton,  Mass.,  in  1912.  In  all  there  were  25  known  and  three 
probable  cases;  of  the  known  cases;  15  gave  positive  agglutination  tests 
with  oi-paratyphoid  bacilli.  Everyone  of  the  25  patients  used  the  sus- 
pected milk.  The  original  infection  of  the  milk  occurred  on  one  of  the 
dairy  farms  that  supplied  the  implicated  route  but  there  was  reason  for 
believing  that  later  some  of  the  milk  was  infected  by  an  employee  of  the 
retailer,  who  had  contracted  the  fever  by  drinking  the  infected  milk  from 
the  dairy  farm.  In  the  affected  communities  no  cases  of  typhoid  fever 
and  no  other  cases  of  paratyphoid  fever  were  reported  within  the  period 
under  consideration. 

At  Ames,  Iowa,  there  occurred  a  milk-borne  epidemic  of  paratyphoid 
fever  in  which  the  patients'  sera  indicated  B.  paratyphosus  ft  as  the  infect- 
ing organism.  Ten  cases  were  discovered  and  nine  of  the  patients  were 
patrons  of  a  single  milk  dealer.  The  primary  source  of  the  contagion 
was  held  to  be  either  a  carrier  or  a  convalescent. 

Asiatic  Cholera. — Asiatic  cholera  is  caused  by  Sp.  cholerce  which  is 
discharged  in  the  feces  of  the  sick  and  of  carriers;  it  is  readily  spread  by 
fingers  soiled  with  such  evacuations,  by  flies  and  in  every  way  by  which 
transfers  are  made  of  even  infinitesimal  amounts  of  infected  matter, 
to  food  and  to  other  objects  that  afterward  find  their  way  to  the 
mouth  of  man.  It  is  man-borne  and  dogs  the  footstep  of  pilgrims, 
caravans,  emigrants  and  armies.  It  is  often  spread  from  port  to  port 
by  carriers.  Drinking  water  is  frequently  infected  with  it  and  has 


DISEASES  COMMUNICABLE  IN  MILK  69 

caused  serious  epidemics.  The  vibrio  requires  a  neutral  or  slightly  alka- 
line medium  for  growth  and  apparently  for  this  reason  milk  has  played 
a  less  prominent  part  in  its  spread  than  has  other  food,  since,  as  in  typhoid 
fever,  the  lactic  organisms  exert  a  protective  action.  Alexandrine  and 
Sampeto  found  that  the  limit  of  acidity  the  vibrio  will  stand  in  milk  is 
less  than  1  per  cent,  calculated  as  lactic  acid.  In  their  experiments  the 
cholera  vibrios  lived  in  ordinary  milk  at  room  temperature  11  to  63 
hours  or  until  prohibitive  acidity  had  been  reached.  At  98.7°F.  the 
vibrios  usually  disappeared  in  6  to  8  hr.  Kendall,  Day  and  Walker  found 
that  in  pure  culture  the  vibrios  produced  acid  coagulation  of  milk  by  the 
end  of  the  third  day. 

Simpson,  the  health  officer  of  Calcutta,  reported  that  nine  cases  of 
cholera  occurred  on  a  ship  there,  10  of  whose  men  had  obtained  milk  from 
a  native.  One  drank  but  little  of  the  milk  and  escaped,  four  died  of 
cholera  and  five  were  very  sick  with  diarrhea.  Eight  others  who  had  con- 
densed milk  only  and  who  did  not  touch  the  suspected  milk  were  not  ill. 
Dejecta  from  a  cholera  patient  found  access  to  a  water  tank  near  the 
dairy  and  the  milkman  confessed  diluting  his  milk  one-fourth  with  water 
from  the  tank. 

Heine  and  others  have  shown  that  the  cholera  spirillum  soon  dies  out 
in  butter  and  he  failed  to  find  the  organism  after  1  or  2  days  in  cheese. 

The  paucity  of  well- authenticated  epidemics  of  this  disease  attribut- 
able to  milk,  together  with  the  other  facts  that  have  been  given  regarding 
the  limited  life  of  the  vibrios  in  milk  and  its  products,  indicate  that 
relatively  milk  is  not  an  important  factor  in  disseminating  the  disease. 

Diphtheria. — Diphtheria  is  caused  by  B.  diphtheria  and  is  spread  in  the 
secretions  of  the  mouth  and  nose.  Droplet  infection  and  infection  from 
objects  mouthed  or  handled  either  by  those  ill  with  the  disease  or  by 
bacillus  carriers  are  common  modes  of  infection.  Milk  is  often  the  medium 
through  which  the  contagion  is  spread.  The  first  epidemic  in  the  United 
States  attributed  to  milk  seems  to  be  that  in  the  cities  of  Maiden  and 
Melrose,  Mass.,  in  1886.  Hart  and  Busey,  and  Kober  list  28  milk-borne 
epidemics  and  Trask  23,  making  51  in  all;  many  others  must  have  oc- 
curred. Of  Trask's  outbreaks,  15  occurred  in  the  United  States  and 
eight  in  Great  Britain. 

Scarlet  Fever. — Scarlet  fever  seems  to  be  spread  in  the  secretions  of 
the  nose,  throat  and  respiratory  passages  and  in  purulent  discharges  from 
the  ears.  Hart  and  Busey,  and  Kober  list  74  epidemics  due  to  milk;  to 
these  maybe  added  51  gathered  by  Trask,  making  125  in  all.  Of  Trask's 
51  outbreaks  25  were  in  this  country  and  26  in  Great  Britain.  The  first 
recorded  outbreak  attributed  to  milk  in  the  United  States  appears  to  be 
that  at  Putnam,  N.  Y.,  in  1890. 

Septic  Sore  Throat. — Is  a  malady  that  is  characterized  by  a  sudden 
onset,  high  and  irregular  fever,  inflammation  of  the  fauces,  marked  en- 


70  CITY  MILK  SUPPLY 

largement  of  the  cervical  glands,  particularly  in  the  case  of  children  and  a 
course  much  longer  and  attended  with  many  more  complications  than  the 
usual  types  of  tonsillitis.  The  joints  often  are  affected  and  the  heart 
and  kidneys  seriously  damaged;  middle  ear  disease  and  erysipelas  may 
appear,  pneumonia  and  peritonitis  sometimes  develop  and  terminate 
fatally.  In  the  principal  epidemics  that  have  been  studied  in  this  country 
the  incidence  of  the  disease  has  been  greater  among  females  than  males. 
In  the  Cortland-Homer  epidemic  57  per  cent,  of  the  cases  were  of  females; 
in  Concord  58  per  cent.;  in  Baltimore  58  per  cent.,  and  in  Rockville  Center 
59  per  cent.  In  the  Baltimore  epidemic  the  fauces  appeared  to  be  the 
portal  of  entry  but  in  some  cases  there  was  some  question  whether  en- 
trance to  the  body  was  not  obtained  in  some  other  way.  The  disease 
is  now  recognized  to  be  caused  by  a  0  hemolytic  streptococcus  of  the  Smith 
type.  The  incubation  period  is  about  3  days;  the  length  of  illness  varies 
with  the  severity  of  the  attack  and  the  complications  that  develop. 

Savage's  list  of  outbreaks  of  septic  sore  throat  shows  that  extensive 
epidemics  occurred  at  Guilford  and  Colchester,  England,  and  at  Christi- 
ania,  Norway,  before  the  disease  was  recognized  in  the  United  States. 
Here,  septic  sore  throat  was  first  known  as  such  and  studied  by  modern 
methods  in  the  epidemic  that  occurred  in  Boston,  Mass.,  in  1911.     Wins- 
low  who  made  a  study  of  the  epidemic  pointed  out  that  before  the  Boston 
outbreak  occurred  the  disease  prevailed   in    prosodemic   form   in   the 
region  where  the  infected  milk  was  produced  and  he  has  described  an 
epidemic  that  occurred  in  Westchester  County,  New  York,  which  was 
also  prosodemic  but  on  which  a  milk-borne  outbreak  was  superposed,  and 
Frost  in  the  Baltimore  epidemic  attributed  some  cases  to  this  mode  of 
dissemination.     So  the  disease  is  not  necessarily  caused  by  infected 
milk;  it  may  be  spread  by  contact  infection.     This  accords  with  what  is 
now  known  of  the  bacteriological  aspect  of  the  disease  for  the  Smith 
streptococcus  is  primarily  a  human  infection ;  it  causes  carrier  cases  and  it 
infects  milk  chiefly  by  being  transferred  through  the  teat  canal  and  wounds 
to  the  udder  of  the  cow  where  it  proliferates  and  causes  massive  infection 
of  the  milk  which  gives  rise  to  the  widespread  epidemics  that  have  f ocussed 
attention  on  the  disease.     In  one  instance  a  bottle  infection  has  been  de- 
scribed and  it  has  been  held  that  milk  has  been  infected  by  an  infected 
person  who  handled  it.     Much  patient  investigation  has  been  required  to 
reach  this  correct  understanding  of  the  disease  for  at  first,  owing  to  the 
fact  that  the  causative  organism  was  a  streptococcus  and  that  mastitis 
was  known  to  be  often  caused  by  streptococci,  suspicion  was  directed 
to  the  cow  and  all  garget  cases  were  regarded  as  potentially  dangerous, 
although  herdsmen  and  others  who  were  familiar  with  cows  thought  it 
improbable  that  mastitis  which  is  so  common  could  more  than  very 
exceptionally  be  the  cause  of  contagion.     Mistrust  of  the  udder-sick  cow 
was  deepened  by  the  discovery  of  cases  of  mammitis  in  some  of  the  herds 


DISEASES  COMMUNICABLE  IN  MILK  71 

supplying  the  infected  milk,  though  in  some  instances  the  presence  of  sore 
throat  in  the  family  of  the  proprietor  raised  the  question  whether  these 
throats  bore  any  relation  to  the  epidemic,  and  if  so  whether  they  were 
the  cause  of  direct  infection  of  the  milk,  or  of  indirect  infection  by  infecting 
the  udders,  or  whether  they  were  not  themselves  derived  from  the  cases  of 
garget  in  the  herd.  So  the  questions  of  whether  the  cow  was  infected  by 
humans  and  of  the  pathogenicity  to  man  of  the  streptococci  causative 
of  garget  were  raised. 

The  investigations  and  experiments  of  Savage  in  England,  of  Ruediger, 
and  of  Davis  and  Capps  in  this  country  were  important  in  helping  to 
solve  these  questions,  for,  taken  together,  they  indicated  that  the  strepto- 
coccus, which  is  ordinarily  the  cause  of  garget,  is  not  pathogenic  for  man, 
that  the  blood  agar  plate  may  be  used  to  distinguish  St.  lacticus  from 
St.  pyogenes,  which  is  found  in  human  throats,  and  that  cows  cannot  be 
infected  with  streptococci  of  human  origin  by  smearing  them  on  the 
udder,  but  that  they  may  be,  either  by  abrading  the  teat  slightly  near  the 
teat  canal  and  applying  the  cultures,  or  by  injecting  them  a  short  dis- 
tance into  the  udder. 

Study  of  Smith  and  Brown. — Theobald  Smith  and  J.  H.  Brown  studied 
hemolytic  streptococci  associated  with  outbreaks  of  milk-borne  tonsillitis 
in  five  Massachusetts  cities,  and  compared  them  with  those  isolated  in 
other  epidemics.  They  point  out  that  mammitis  is  a  disease  that  is  due 
to  injury  and  subsequent  infection  of  the  udder  and  that  it  is  prevalent 
at  all  seasons  of  the  year,  whereas  septic  sore  throat  prevails  mostly  in 
the  transition  period  between  winter  and  spring  when  throat  affections 
in  man  are  common,  and  furthermore  that  in  septic  sore  throat  outbreaks 
due  to  milk,  the  milk  remains  infected  for  a  long  time.  They  suggest  that 
the  grafting  of  human  streptococci  on  the  udder  in  milking  and  in  other- 
wise manipulating  the  udder,  and  their  subsequent  development  therein 
afford  a  reasonable  explanation  of  outbreaks  of  the  disease.  There  is  no 
evidence  that  the  streptococci  that  are  responsible  for  garget  are  the  oc- 
casion of  outbreaks  of  septic  sore  throat  but  it  is  conceivable  that  in 
an  inflamed  udder  both  bovine  and  human  streptococci  might  be  found, 
in  which  cases  the  latter  should  be  regarded  as  an  added  infection. 
The  observations  of  Smith  and  Brown  and  of  others  indicate  that  when 
infections  of  the  udder  with  human  streptococci  do  occur,  physical  mani- 
festations in  the  udder  are  very  slight  if  noticeable  at  all. 

As  a  result  of  their  research  these  two  investigators  isolated  two  strep- 
tococci that  they  held  responsible  for  septic  sore  throat.  One,  outbreak 
A,  was  altogether  singular,  in  that  the  fermentations  it  produced  with 
sugars  were  different  from  those  produced  by  streptococci  that  caused 
the  other  outbreaks  which  they  studied.  These  latter  proved  to  be 
identical  with  the  streptococci  that  caused  all  the  epidemics  investigated 
by  others. 


72  CITY  MILK  SUPPLY 

The  other  streptococcus  was  isolated  in  one  outbreak,  from  a  cow  in 
the  suspected  herd  and  was  different  from  hemolytic  udder  streptococci 
in  the  same  herd  and  from  those  of  the  herd  in  outbreak  A. 

The  udder  of  this  cow  had  been  injured  and  one  quarter  which  was 
inflamed  gave  a  thick  curdy  product;  the  three  other  quarters  were 
apparently  unaffected  but  the  milk  from  the  inflamed  quarter  did  not  give 
hemolytic  streptococci  in  the  cultures,  whereas  the  mixed  sample  of  milk 
from  the  three  quarters  that  seemed  sound  contained  human  streptococci. 
This  type  was  wholly  identical  with  streptococci  from  the  throats  of  three 
human  cases,  one  of  them  fatal,  and  in  another  outbreak  it  was  isolated 
from  mixed  milk.  This  organism  is  now  regarded  as  the  usual  cause  of 
septic  sore  throat  and  is  referred  to  as  the  /3  hemolytic  streptococcus  of  the 
Smith  type  or  briefly  as  the  Smith  streptococcus.  The  strains  studied 
differed  slightly  among  themselves,  as  to  form  of  the  colonies  and  othei 
cultural  characteristics.  On  horse-blood  agar  plates  the  colonies  formed 
a  sharply  defined,  clear,  transparent,  completely  hemolyzed,  colorless 
zone  2  to  4  mm.  in  diameter;  they  were  simple  and  biconvex  and  never 
complex.  In  bouillon  the  growth  of  the  several  strains  varied  from  a 
well-clouded  suspension  with  flocculent  sediment  to  a  perfectly  clear 
bouillon  with  abundant  fleecy  sediment.  The  great  clouding  was  associ- 
ated with  the  shorter  chains.  In  7  days,  cultures  in  milk  coagulated  on 
heating.  In  bouillon  after  24  hr.  incubation,  the  chains  were  composed  of 
round  flattened  cells,  that  is,  with  the  transverse  axis  the  greater  with 
occasional  cells  that  were  elongated.  This  streptococcus  fermented 
dextrose,  maltose,  saccharose,  lactose  and  salicin  with  the  production  of 
acid,  but  did  not  ferment  mannit,  raffinose  or  inulin.  Injected  intraven- 
ously into  rabbits  in  a  definite,  uniform  dose  it  produced  a  febrile  reaction 
lasting  1  to  4  days  or  over  a  week,  followed  by,  or  accompanying,  a  local- 
ization affecting  the  hip,  shoulder,  knee,  wrist,  and  foot.  In  the  more 
acute  cases  foci  occurred  in  the  kidneys  and  heart.  These  streptococci 
were  identical  with  streptococci  that  were  held  by  other  bacteriologists 
to  be  causative  of  the  epidemics  of  septic  sore  throat  in  Boston  in  1911,  and 
Baltimore  and  Chicago  in  1912  which  were  found  to  be  identical  with  each 
other. 

The  streptococci  that  have  caused  the  recent  outbreaks  of  septic  sore 
throat  are  alike  in  that  immediately  around  the  colonies  is  produced  a  clear 
hemolyzed  area  on  blood  agar  plates;  but  these  hemolytic  colonies  are  to 
be  carefully  distinguished  from  the  colony  of  the  common  throat  coccus, 
which  has  a  partly  discolored  and  hemolyzed  mantle  between  the  colony 
proper  and  the  outer,  narrower  hemolyzed  zone. 

Study  of  Krumwiede  and  Valentine. — This  work  was  amply  con- 
firmed by  Krumwiede  and  Valentine  who  investigated  an  outbreak  of 
septic  sore  throat  that  occurred  at  Rockville  Center,  Long  Island,  N.  Y., 
in  June,  1914.  The  infection  was  on  the  route  of  a  dairy  that  daily 


DISEASES  COMMUNICABLE  IN  MILK  73 

distributed  400  qt.  of  milk  to  175  customers.  All  the  other  dairymen 
together  distributed  1,200  qt.  of  milk.  The  infected  dairy  had  205 
out  of  232  cases;  therefore,  though  it  delivered  but  25  per  cent,  of  the 
milk,  it  had  at  least  90  per  cent,  of  the  cases.  Most  of  the  milk  of  the 
infected  dairy  came  from  a  herd  of  22  cows  at  Oceanside  but  in  part 
the  milk  came  from  two  smaller  dairies,  R  and  C.  All  three  of  them  were 
investigated. 

At  Oceanside  it  was  found  that  the  daughter  of  the  owner,  Miss  W., 
developed  sore  throat  on  April  16.  Her  mother  came  down  with  it  on 
May  9;  she  claimed  to  have  been  absent  from  the  dairy  until  May  28. 
A  driver  took  the  disease  on  May  11  and  a  milker  on  June  9.  The  greater 
part  of  the  milking  was  done  by  the  owner  and  a  milker  but  the  driver 
sometimes  helped.  On  April  21,  May  17  and  May  21  isolated  cases  of 
sore  throat  appeared  among  the  customers.  On  May  30  two  cases  ap- 
peared in  a  family  that  had  its  own  cow;  these  cases  and  those  at  the 
farm  seem  to  have  been  of  sporadic  and  contact  origin. 

The  material  that  was  examined  bacteriologically  consisted  of  moist 
swabs  from  the  throat  of  every  individual  on  the  three  farms  supplying 
the  infected  dairy  and  from  a  number  of  cases,  as  well  as  from  a  culture 
from  a  complicating  case  of  peritonitis.  Milk  from  each  quarter  of  all 
the  cows  was  put  on  ice  over  night  and  smears  from  the  sediment  were 
examined. 

Five  of  the  cows  showed  moderate  numbers  of  streptococci  in  one  or 
more  quarters  and  one  of  the  animals  gave  physical  evidence  of  mastitis. 
Another  cow  showed  moderate  numbers  of  streptococci  in  two  quarters 
and  enormous  numbers  of  streptococci  from  one-quarter.  Milk  from  this 
quarter,  owing  to  coagulation  of  the  casein  and  separation  of  the  whey, 
was  flocculent. 

All  positive  samples  of  milk  were  inoculated  on  blood  agar  plates. 
The  cultures  from  cows  2,  3,  4,  5  and  6  showed:  on  blood  agar  plates,  no 
hemolyses;  on  washed  blood  cells,  no  hemolysis;  no  fermentation  of  inulin, 
raffinose,  and  mannit;  fermentation  of  salicin.  The  milk  from  three- 
quarters  of  cow  21  showed:  hemolysis  of  blood  agar  plates;  hemolysis  of 
washed  blood  cells;  no  fermentation  of  inulin,  raffinose,  and  mannit; 
fermentation  of  salicin. 

Twelve  cases  of  septic  sore  throat  were  studied  and  hemolytic  strep- 
tococci in  varying  percentages  were  found  present.  Pure  cultures  were 
isolated  from  each  case  and  usually  not  only  several  hemolyzing  but 
also  several  non-hemolyzing  types  were  found.  At  the  Oceanside 
dairy  hemolyzing  types  were  obtained  from  the  driver,  milker  and  a  wash- 
woman who  had  enlarged  tonsils  but  denied  illness;  no  hemolyzing  types 
were  obtained  from  Mrs.  W.  At  Farms  R  and  C  there  had  been  no  cases 
of  illness  and  no  hemolyzing  types  were  found  except  from  Mrs.  R.  who 
had  enlarged  tonsils.  The  non-hemolyzing  types  were  studied  only  in 


74  CITY  MILK  SUPPLY 

relation  to  similar  ones  isolated  from  the  five  cows.  Most  strains  could 
be  excluded  because  of  fermentative  and  other  reactions.  Very  few  had 
characteristics  of  the  bovine  strains  and  nearly  all  came  from  the  non- 
exposed  on  farms  R  and  C;  consequently  the  non-hemolyzing  strains 
were  excluded  from  consideration  as  the  caustive  organism. 

The  hemolyzing  types  obtained  from  the  throats  of  the  cases,  from 
the  throats  of  persons  at  the  Oceanside  dairy  and  the  culture  from  a 
complicating  case  of  peritonitis,  had  the  same  cultural  characteristics 
and  were  similar  to  the  hemolyzing  strain  from  cow  2 1 .  But  one  hemolyz- 
ing strain  was  isolated  from  the  non-exposed,  to  wit,  from  Mrs.  E.  R.  on 
farm  R,  but  this  strain,  though  it  gave  the  same  sugar  fermentations,  was 
different  from  the  other  hemolyzers  in  other  cultural  reactions,  its  mor- 
phology and  other  characteristics. 

The  isolation  of  a  distinct  race  of  streptococci  from  the  throats  of 
the  cases,  from  a  complicating  peritonitis  and  also  from  the  throats  of 
persons  and  from  a  cow  on  one  dairy  farm,  together  with  the  absence  of 
this  streptococcus  in  the  throats  of  persons  on  other  farms,  when  consid- 
ered in  connection  with  the  epidemiological  data,  viz.,  the  presence  of 
sore  throat  on  the  one  farm  before  the  general  outbreak,  makes  it 
practically  certain  that  the  following  sequence  of  events  occurred.  Miss 
W.,  was  infected  on  April  16  and  by  contact  infection  gave  sore  throat 
to  Mrs.  W.  on  May  9.  From  one  of  the  two  the  driver  became  infected 
on  May  11  and  either  he  or  Mrs.  W.,  probably  the  latter,  infected  the 
cow.  Multiplication  of  the  organism  in  the  milk  ducts  and  in  the  milk 
itself  with  contamination  of  the  mixed  milk  occurred,  culminating  in 
the  outbreak. 

"Therefore  it  is  concluded  that  the  facts  give  strong  added  evidence  to  the 
view  that  infection  in  milk-borne  septic  sore  throat  is  of  human  and  not  of  bovine 
origin.  The  fact  that  the  cow  infected  with  'human'  streptococci  had  no  phys- 
ical evidence  of  mastitis  whereas  another  cow  having  mastitis  yielded  another 
unrelated  'bovine'  variety  of  streptococcus  is  also  of  value  as  evidence  in  this 
connection.  Previous  investigations  have  shown  that  some  types  of  'human' 
streptococci  can  multiply  for  a  shorter  or  longer  period  in  the  udder  without 
producing  evidence  of  mastitis." 

Krumwiede  and  Valentine  conclude  that: 

"Streptococci,  similar  culturally  and  identical  in  their  agglutination,  were 
isolated  from  cases  of  septic  sore  throat  and  from  the  udder  of  one  cow  which 
showed  no  evidence  of  mastitis,  except  the  peculiar  character  of  the  milk  from 
one-quarter.  Both  the  bacteriological  and  epidemiological  facts  show  that  the 
infection  was  primarily  of  human  origin.  The  streptococci  in  the  various  epi- 
demics, including  this  Rockville  Center  epidemic,  have  all  been  the  same  cultur- 
ally with  one  exception,  namely  '  outbreak  A '  of  Smith  and  Brown.  In  tracing 
the  source  of  such  an  epidemic,  the  effort  should  be  toward  finding  cases  of  sore 
throat  among  those  engaged  in  producing  milk,  not  mastitis  in  the  cow  alone. 


DISEASES  COMMUNICABLE  IN  MILK  75 

If  human  streptococci  are  found  in  mastitis,  they  are  most  likely  secondary 
agents  in  an  already  existing  inflammation  due  to  bovine  strains.  The  strepto- 
cocci in  different  epidemics  differ  culturally  and  those  similar  culturally  differ  in 
their  immunity  reactions.  Cultural  similarity  of  strains  from  man  and  cattle 
is  insufficient  to  prove  their  identity;  cultural  identity  in  every  detail  or  irnmuno- 
logical  identity  is  essential." 

In  the  course  of  the  investigation  the  following  practical  points  were 
developed:  (1)  Few  hemolytic  types  may  be  found  even  when  the  swabs 
are  directly  inoculated  upon  blood  agar;  they  may  be  lost  on  Loeffler 
blood-serum  smears  submitted  for  examination.  (2)  On  surface  streaked 
blood  plates,  typical  hemolytic  colonies  may  not  be  present,  though 
on  longer  incubation  they  may  develop.  (3)  For  the  determination  of 
sugar  fermentation,  serum  water  is  unsuited.  All  of  the  type  strains 
failed  to  ferment  salicin,  using  this  medium,  although  prompt  fermenta- 
tion took  place  using  serum  broth  or  serum  water  containing  1  per  cent, 
of  peptone. 

Studies  of  Smillie. — In  forthcoming  work,  now  in  press,  Dr.  W.  G. 
Smillie  develops  the  following  points: 

1.  His  investigations  of  epidemics  of  septic  sore  throat  confirm  the 
work  of  Smith  and  Brown. 

2.  Though  the  Smith  streptococci  usually  disappear  from  the  throat 
of  the  patient  within  3  weeks  after  the  passing  of  the  clinical  symptoms 
they  may  persist  for  4  months  and  possibly  longer. 

In  a  small  outbreak  in  a  hospital  he  discovered  the  source  to  be  a 
nurse  who  4  months  before  had  contracted  the  disease  in  a  milk-borne 
epidemic  and  who  as  a  carrier  was  conveying  the  disease  to  others  by 
contact  infection. 

3.  Out  of  100  normal  throats  examined,  60  per  cent,  being  those  of 
adults  and  40  per  cent,  those  of  children,-  but  one  yielded  the  Smith 
streptococcus. 

He  studied  the  throats  of  25  persons  who  within  2  years  had  suffered 
attacks  of  milk-borne  septic  sore  throat  and  among  them  found  but  one 
carrier,  the  nurse  in  the  hospital. 

4.  In  a  study  of  25  cases  of  ordinary  tonsillitis  he  found  that  about  one- 
half  were  due  to  the  Smith  streptococcus.     Tonsillitis  on  the  dairy  farm, 
therefore,  should  not  be  regarded  lightly,  for  it  may  be  the  source  of  serious 
milk  infection. 

5.  In  a  study  of  scarlet  fever  cases  he  found  that  most  severe  cases, 
and  some  of  the  moderate  and  mild  cases  harbored  the  Smith  streptococ- 
cus in  their  throats.     He  believes  that  a  case  of  scarlet  fever  may  infect 
the  milk  or  the  udder  of  the  cow  with  Smith  streptococcus.     So  there 
may  result  from  a  scarlet  fever  case  milk-borne  cases  of  (a)  scarlet  fever, 
or  (6)  septic  sore  throat  or  (c)  a  mixed  infection  of  the  two. 


76 


CITY  MILK  SUPPLY 


Summary  of  Epidemics. — In  Table  30  are  set  forth  some  of  the  lead- 
ing facts  concerning  the  principal  epidemics  in  this  country.  The  wide- 
spread serious  character  of  the  outbreaks,  taken  into  consideration  with 
the  fact  that  in  many  of  them  the  management  of  the  dairies  was  more 
than  usually  intelligent  and  conscientious,  convinced  the  experts  who  in- 
vestigated them  that  the  health  of  milk  consumers  could  be  effectively 
protected  only  by  pasteurizing  the  milk  under  thorough  inspection. 

TABLE  30. — PRINCIPAL  EPIDEMICS  OF  SEPTIC  SORE  THROAT  IN  THE  UNITED  STATES 


Date  and  place 

Number 
of  cases 

Males 

Females 

Deaths 

Age    distribution,    percentage    of 
cases  in  each  age  period,  years 

Be- 
low 
11 
years 

11-20 
years 

21-30 
years 

31-40 
years 

41-50 
years 

A- 
bove 
50 
years 

May,  1911,  Boston, 
Mass 

l,043(a) 
1,000-3,000 

10,000 
1,000 

669 
232 
905 

215 
201 

522  (c) 
383  (d) 

48 
30  or  more 

(6) 

53 

Dec.  2  to  May  10,  1911, 
Baltimore,  Md  .  .  . 

12 

15 

10 

6 

5 

December,  1911,  to  Feb- 
ruary, 1912,  Chicago, 
111 

Jan.  1  to  Feb.  15,  1912, 
Concord   N  H 

119(e) 
286 

376 

162  (/) 

383 
147 
517 

18 

15 
29 
25 

16 
13 
16 

42 

18 
22 
20 

22 

19 
20 
21 

13 

• 
9 

11 

18 

20 
8 
6 

April  20  to   May   10, 
1913,  Cortland-Homer, 
N.  Y  

14 

June,  1914,  Rockville, 
N  Y 

January  to  May,  1915, 
Weschester  Co.,  N.  Y.  . 

(a)  Including  Brookline  and  Cambridge. 

(fe)   Figures  for  Cambridge  alone;  under  15  years,  15;  16  to  25  years,  20;  and  over  20  years,  64. 

(c)  306  patients  whose  sex  is  unknown. 

(d)  85  patients  of  unknown  sex. 

(e)  Besides  these  were  128  boys  in  St.  Paul's  School. 

(/)  Besides  these  there  were  25  girls  in  St.  Mary's  School. 

Mode  of  Transmission  of  Infectious  Disease. — Having  named  the 
diseases  that  are  transmitted  by  milk,  the  ways  in  which  they  infect  it 
must  be  considered.  In  the  first  place,  it  should  be  recognized  that  there 
are  two  sources  of  danger,  animals  and  men.  Of  these  the  former 
are  the  least  important  for,  with  the  exception  of  septic  sore  throat, 
which  primarily  is  of  human  origin,  and  of  bovine  tuberculosis,  not  many 
of  their  diseases  are  communicable  to  man  and  those  that  are  so  are 
relatively  rare.  The  virus  of  a  few  of  them  such  as  tuberculosis,  foot- 
and-mouth  disease  and  septic  sore  throat  are  in  the  milk  as  it  comes  from 
the  udder.  Tubercle  bacilli  also  are  contained  in  the  feces  of  dis- 
eased cows  which  dropping  into  the  milk  infect  it.  Milk  may  also  be 
infected  by  droolings  from  the  animals  and  by  pustular  and  vesicular 


DISEASES  COMMUNICABLE  IN  MILK  77 

discharges  from  eruptions  on  the  udder.  All  such  infectious  matter 
may  be  carried  to  the  milk  on  the  hands  of  uncleanly  careless  milkers. 

The  virus  of  human  disease  is  contained  in  the  urine  and  excrement 
and  in  the  discharges  of  the  mouth,  nose  and  ears  of  those  who  have  com- 
municable disease.  Epidemiologists  distinguish  several  states  in  which 
people  may  disseminate  contagion.  There  are  those  in  the  prodromal 
stage,  that  in  which  the  malady  is  developing  in  their  system.  Such 
people  may  infect  the  milk;  in  typhoid  fever,  for  instance,  the  victim 
may  eliminate  the  specific  germs  for  as  long  as  10  days  before  the  pre- 
monitory symptoms  appear.  There  are  those  who  are  actually  sick. 
They  form  two  groups ;  those  who  are  severely  ill  and  so  betake  themselves 
to  bed  and  those  with  mild  or  walking  cases,  who  feel  mean  or  perhaps  only 
excessively  tired  so  that  they  do  not  give  up  work  but  continue  thereat 
as  usual.  Of  these  two  groups  both  are  dangerous  but  the  latter  are 
very  much  more  so  than  the  former  for  they  can  hardly  avoid  infecting 
the  milk  if  they  have  to  handle  it.  From  this  group  the  "missed" 
cases  arise,  cases  so  very  mild  that  their  existence  is  never  detected. 
They  form  an  important  source  of  communicable  disease  and  at  least 
one  widespread  milk-borne  epidemic  has  been  ascribed  to  such  an  origin. 
Finally  there  are  the  carriers  of  which  there  are  three  sorts,  the  acute, 
the  chronic  and  the  temporary.  An  acute  carrier  is  one  who  discharges 
pathogenic  microorganisms  for  a  few  weeks  after  recovery.  Such  a  one, 
on  returning  to  his  duties,  may  be  the  cause  of  an  outbreak.  The 
chronic  carriers  are  those  who  for  months  or  years  after  recovery  harbor 
and  scatter  about  the  germs  of  the  disease  that  afflicted  them.  Some- 
times intermittent  chronic  carriers  are  spoken  of;  the  appelation  signifies 
that  they  discharge  the  specific  germs  for  a  while  and  then  stop  doing 
so  only  to  begin  again  later.  It  is  only  of  late  years  that  the  existence 
of  carriers  has  been  recognized  but  they  are  now  and  the  number  of 
outbreaks  that  are  traced  to  them  increases  steadily.  The  temporary 
carriers  are  those  who  never  have  had  communicable  disease  themselves 
but  who  by  contact  with  those  who  have,  become  for  a  short  time  dis- 
tributors of  infection.  To  this  class  belong  those  who  in  nursing  the 
sick  infect  themselves  but  do  not  develop  an  attack  of  the  disease. 

Finally,  contagion  is  spread  by  flies  that  feed  on  the  discharges  of 
the  sick  and  afterward  carry  the  germs  on  their  feet  and  droppings  to 
milk  and  other  foods. 

Transmission  by  Milk. — Milk  may  be  infected  at  various  stages  of 
its  progress  from  the  cow  to  the  consumer,  on  the  farm,  in  transit,  at 
the  city  milk  plant,  in  stores,  and  in  the  home.  The  possibilities  of 
infection  are  taken  up  in  detail. 

Infection  of  Milk  on  the  Farm. — It  is  conceivable  but  not  probable 
that  cows  wading  in  infected  streams  might  infect  their  bellies  and  udders 
with  disease  germs  that  would  fall  into  the  pails  at  milking.  No  flawless 


78  CITY  MILK  SUPPLY 

examples  of  this  having  happened  can  be  cited,  yet  instances  are  known 
where  cities  have  forbidden  the  delivery  of  milk  from  certain  farms 
whereon  the  cows  had  access  to  heavily  polluted  streams. 

Commonly  infection  at  the  farm  is  caused  by  some  one  living  thereon 
contracting  the  disease  and  either  directly  himself  or  indirectly  through 
his  attendants  infecting  the  milk.  It  is  of  prime  importance  to  inculcate 
cleanly  habits  among  those  engaged  in  dairying.  They  should  be  told 
frankly  that  nasal  discharges,  saliva,  feces  and  urine  are  all  likely  to  be 
infectious  and  that  decency  and  safety  alike  require  them  to  refrain  from 
spitting  on  the  hands  at  milking  and  from  blowing  the  nose  with  the 
fingers.  Above  all  the  necessity  of  washing  the  hands  after  attending 
to  the  toilet  should  be  impressed  upon  them.  The  part  played  by  feces, 
fingers  and  flies  in  distributing  infection  should  be  carefully  borne  in 
mind.  Of  epidemics  originating  at  the  farm  a  brief  account  of  a  few 
will  serve  as  examples. 

Milkers  caused  an  outbreak  at  Brookline,  Mass.  Two  of  the  dairy- 
man's children  came  down  with  diphtheria  and  were  removed  to  a  hospital. 
No  diphtheria  bacilli  were  found  in  other  members  of  the  household. 
Three  weeks  later  cases  of  diphtheria  began  to  appear  in  Brookline  in 
four  of  the  seven  or  eight  families  that  used  the  milk.  Reexamination 
of  the  members  of  the  family  and  of  others  handling  the  milk  showed 
virulent  diphtheria  bacilli  in  the  throats  of  three  men,  of  whom  two  were 
at  the  time  milking  the  cows. 

Persons  who  nursed  the  sick  and  also  cared  for  the  milk  caused  16 
cases  of  typhoid  fever  at  Washington,  D.C.,in  1905;  half  of  the  cases  were 
in  the  family  on  the  farm. 

A  mother  who  nursed  members  of  her  family  sick  with  typhoid  fever 
and  also  milked  the  cows  caused  55  cases  of  that  disease  at  Philadelphia 
in  1903. 

Milk  may  be  infected  at  the  farm  through  contact  with  milk  utensils 
such  as  brushes,  strainer  cloths,  cans,  coolers,  separators,  etc.,  which 
have  been  infected  either  by  the  sick  or  those  nursing  them.  At 
Providence,  R.I.,  1895,  31  cases  of  typhoid  fever  and  three  deaths  were 
caused  by  a  mother  who  was  nursing  the  sick,  washing  the  strainer  cloths 
and  utensils.  At  Lynn,  Mass.,  in  1906,  31  cases  of  typhoid  fever  came 
from  a  boy  ill  with  the  disease  washing  the  bottles.  A  person  who  washed 
the  cooler  of  a  dairy  and  at  the  same  time  cared  for  a  child  sick  with 
diphtheria  caused  72  cases  of  that  disease  in  1907  in  Milton,  Dorchester 
and  Hyde  Park,  Mass. 

Water  supplies  on  farms  and  in  milk  plants  are  often  held  responsible 
for  typhoid  fever  outbreaks.  Water  that  is  used  for  washing  utensils, 
cooling  the  milk  or  diluting  it,  may  be  the  source  of  trouble.  The 
outbreaks  that  have  been  attributed  to  washing  utensils  with  polluted 
water  are  very  many.  Fourteen  cases  at  Swampscott,  Mass.,  in  1905 


DISEASES  COMMUNICABLE  IN  MILK  79 

are  believed  to  have  come  from  washing  cans  in  polluted  water.  Eleven 
of  the  cases  were  supplied  by  one  dairyman  who  received  milk  from 
several  farms.  In  the  family  of  one  of  them,  were  two  cases  of  typhoid 
and  of  another  three.  At  one  of  the  farms  a  pail  used  for  discharges  of 
the  patients  was  kept  on  the  curb  of  a  well  the  water  of  which  was  used 
to  wash  cans.  At  York,  Pa.,  in  1899,  66  cases  of  typhoid  fever  and  14 
deaths  were  caused  by  milk  that  is  believed  to  have  been  infected  by 
washing  cans  in  the  water  of  a  spring  near  which  typhoid  dejecta  were 
thrown. 

An  epidemic  in  1892  at  Springfield,  Mass.,  of  125  cases  of  typhoid 
fever  was  attributed  to  milk  which  had  been  cooled  in  a  polluted  well  by 
sinking  the  cans  to  the  bottom  where  they  were  covered  by  3  or  4  ft.  of 
water  and  remained  for  hours  at  a  time.  As  the  stopples  did  not  fit 
tight  the  cans  filled  with  the  polluted  water.  While  this  is  rather  a  gross 
example  of  the  careless  cooling  of  milk  no  one  who  has  observed  the 
manner  and  places  of  cooling  milk  on  many  dairy  farms  can  doubt  that 
a  warning  against  this  sort  of  carelessness  is  needed.  At  Palo  Alto, 
Cal.,  in  1903,  out  of  900  customers  of  one  dairy  232  had  typhoid  fever  and 
all  but  16  of  these  cases  were  primary;  the  milk  cans  were  washed  and 
the  milk  adulterated  with  water  from  a  sewage-polluted  creek. 

But  one  epidemic,  that  at  Hartford,  Conn.,  is  attributed  to  the 
use  of  infected  ice  in  the  dairy;  it  is  doubtful  if  even  this  case  would 
bear  close  scrutiny  in  the  light  of  the  most  recent  knowledge  of  the  ways 
in  which  contagion  is  transmissible.  Ice  is  an  unfavorable  medium  for 
bacteria;  it  has  been  shown  that  40  per  cent,  of  the  typhoid  bacilli  die 
within  3  hr.  after  freezing  and  98  per  cent,  in  2  weeks.  Still,  such  in- 
fection is  conceivable  and  at  the  time  the  epidemic  was  investigated  it 
was  believed  to  be  due  to  the  ice  which  was  cut  on  a  contaminated  pond. 
There  were  30  cases  and  four  deaths  from  typhoid  fever  among  the  cus- 
tomers of  the  dairy  and  they  occurred  only  among  those  that  used  the 
evening  milk.  This  milk  was  submerged  over  night  in  ice  water;  it  was 
only  a  little  while  before  the  epidemic  began  that  this  ice  was  used. 

Occasionally  the  infection  is  brought  to  the  farm  by  children  or 
visitors.  At  Rockford,  111.,  in  1913,  a  dairy  route  was  thought  possibly 
to  have  been  infected  by  a  neighbor's  child  who  had  walking  typhoid 
fever  and  who  was  permitted  to  cap  the  milk  bottles.  In  Norwalk,  Conn., 
a  scarlet  fever  outbreak  appeared  in  1897  that  was  due  to  an  infected  milk 
supply.  The  contagion  was  traced  to  one  of  three  dairy  farms  that 
supplied  the  Norwalk  dealer.  It  seems  that  there  had  been  a  contact 
epidemic  of  scarlet  fever  in  the  district  school  and  that  among  those  who 
caught  the  disease  were  two  children  that  lived  near  the  dairy  farm. 
The  cases  were  very  mild  and  the  youngsters  visited  the  farm  and  played 
with  the  dairyman's  child  who  ultimately  took  the  fever.  The  milk  was 
believed  to  have  been  infected  in  some  way  by  the  children. 


80  CITY  MILK  SUPPLY 

As  long  ago  as  1895,  Kober  pointed  out  that  the  house  fly  might  infect 
milk;  since  that  time  knowledge  of  the  habits  of  that  insect  has  increased 
and  it  is  generally  recognized  to  be  a  factor  in  spreading  typhoid  fever, 
tuberculosis  and  other  diseases.  By  preference  it  lays  its  eggs  in  horse 
manure,  but  it  also  oviposits  in  human  excrement  and  cow  dung.  Fur- 
thermore, it  feeds  on  human  dejecta  so  that  it  carries  away  from  the  ordure 
on  its  bedraggled  legs  and  in  its  infected  intestines  such  disease  germs  as 
happen  to  be  therein  and  it  tracks  or  drops  them  on  whatever  it  happens 
to  alight.  Flies  also  have  the  habit  after  feeding  on  liquid  food  of 
exuding  drops  of  fluid  from  their  proboscides.  These  drops  are  some- 
times sucked  up  again  and  sometimes  are  deposited  on  the  surface  on 
which  the  flies  are  walking.  This  deposited  material  is  derived  from  the 
fly's  crop;  it  is  sometimes  called  " vomit"  and  maybe  infectious.  In  feed- 
ing on  dry  material  the  fly  moistens  it  with  vomit  or  saliva;  this  is  done 
for  instance  when  it  feeds  on  sugar.  Flies  swarm  about  milk  pails,  in 
stables  and  in  milk  houses  and  wherever  milk  is  handled,  so  that  great 
care  should  be  taken  to  screen  such  places  and  to  fight  the  flies  with 
sticky  fly  paper,  traps,  etc.,  but  poison  fly  paper  should  not  be  tolerated 
about  a  dairy.  While  it  is  difficult  to  prove  that  flies  have  infected  the 
utensils  or  milk  of  any  dairy  it  is  a  fact  that  they  have  been  strongly 
suspected  of  doing  so.  Consequently  great  care  should  be  taken  to 
make  privies  on  dairy  premises  fly  proof .  Also,  employees  should  not  be 
allowed  to  defecate  on  the  ground  near  the  dairy  nor  should  stools  be 
thrown  on  the  manure  heap.  Likewise,  the  house  slops  should  be  prop- 
erly disposed  of  and  not  thrown  out  on  the  ground  where  flies  can  get 
at  them. 

In  some  dairies  cats  are  given  free  run  of  the  barns  to  catch  mice; 
they  are  apt  to  be  much  in  evidence  at  milking  time  and  are  not  slow  to 
get  at  a  pail  of  milk  that  a  milker  sets  down  for  a  moment.  Rarely,  cats 
become  infected  with  diphtheria  and  possibly  other  disease  and  there 
is  a  bare  chance  that  this  might  happen  with  unhappy  consequences  in 
a  dairy. 

Infection  of  Milk  Enroute  to  the  Creamery  or  City. — After  milk 
leaves  the  farm  there  is  the  chance  that  it  may  be  infected  on  the  way  to 
the  creamery  or  railroad  station  or  in  the  course  of  the  journey  to  the 
city  if  the  cans  in  which  shipment  is  made  are  unsealed.  In  some  com- 
munities milk  is  picked  up  from  several  farms  by  a  single  driver  and 
hauled  to  its  destination.  There  is  apt  to  be  more  or  less  shifting  about 
of  the  cans  on  the  trip  and  there  may  be  some  dumping  of  milk  from  one 
can  to  another  so  that  if  the  handler  should  happen  to  be  a  carrier  or 
diseased,  the  milk  might  get  infected. 

On  the  trip  to  the  city  unsealed  cans  are  apt  to  get  opened  and  the 
contents  may  even  be  sampled  by  the  curious.  This  is  more  likely  to 
happen  in  trolley  and  baggage  cars  to  which  the  public  has  access  than 


DISEASES  COMMUNICABLE  IN  MILK  81 

in  regular  milk  cars.  In  some  cases  the  cans  are  transferred  from  one 
train  to  another  and  if  this  is  done  carelessly  the  milk  may  be  exposed 
to  pollution  and  perhaps  infection.  However,  if  milk  is  infected  in  these 
ways  it  is  only  infrequently,  but  the  possibility  of  such  mishap  should 
be  recognized  and  guarded  against. 

Infection  of  Milk  in  the  City  Milk  Plant.— In  the  city  milk  plant, 
milk  is  exposed  further  to  accidental  infection.  It  is  customary 
at  many  plants  to  taste  the  milk  before  accepting  it  in  order  to  prevent 
any  which  is  off  flavor  being  included  in  the  daily  output.  Where  the 
milk  is  simply  smelled,  or  tasted  from  a  cup,  which  is  filled  with  a  ladle 
there  is  no  danger  but  where  the  cup  is  dipped  into  the  cans  there  is 
danger  that  the  milk  may  be  infected  either  from  the  fingers  or  saliva  of 
the  tester. 

Afterward  in  the  dumping  of  the  milk  from  the  cans  into  vats  and 
in  the  course  of  its  journey  through  the  various  machines  which  it  passes 
until  at  last  it  is  bottled  and  capped,  it  comes  into  contact  with  numerous 
employees  and  anyone  of  them,  if  diseased  or  a  carrier,  may  infect  it. 
That  the  possibility  of  milk  being  infected  after  its  arrival  in  the  city  is 
not  fanciful  is  shown  by  the  experience  of  Rockford,  111.,  in  1913,  where 
the  milk  of  no  less  than  three  different  contractors  was  received  pure 
from  the  farmers  but  in  various  ways  was  infected  before  delivery  to 
the  public.  As  an  instance  of  infection  of  the  milk  in  transferring  it 
from  the  cans  in  which  it  arrives  to  others  may  be  cited  the  Somerville 
epidemic  of  1892.  The  milk  was  brought  in  the  shipping  cans  to  the 
milk  plant  where  it  was  mixed  in  a  large  tank  and  drawn  off  through 
faucets  at  the  bottom  into  smaller  cans  for  delivery  to  the  trade.  One 
of  two  brothers  who  attended  to  the  work  in  the  dairy  had  walking  ty- 
phoid fever;  consequently  there  resulted  30  cases  of  typhoid  fever  among 
the  customers. 

Infection  of  Milk  by  Cans  and  Bottles.— One  of  the  serious  problems 
of  infection  that  both  producers  and  retailers  have  to  meet  is  that  which 
arises  from  the  steady  flow  of  cans  and  bottles  to  the  public  and  back 
again.  Some  of  them  get  into  shops  and  homes  where  there  is  contagion 
or  are  handled  by  carriers  at  some  stage  of  the  journey.  Consequently 
they  come  back  to  the  farm  or  milk  plant  in  an  infected  condition  and 
communicate  disease  to  those  that  handle  them  or  to  customers  if  they 
are  sent  out  again  without  thorough  sterilization.  Likewise  bottles 
and  cans  may  be  infected  at  the  milk  plant  or  farm  by  being  filled  with 
milk  from  cows  suffering  with  disease  communicable  to  man  so  that  if 
these  cans  are  picked  up  by  dairymen  and  used  without  sterilization 
the  milk  from  their  own  healthy  herds  may  become  infected  and  distrib- 
ute the  disease.  As  an  instance  of  this  sort,  the  infection  with  septic 
sore  throat,  of  the  routes  of  several. of  the  dairymen  of  Batavia,  111., 
through  the  use  of  the  bottles  of  Dairy  X  may  be  cited.  Can  and 


82  CITY  MILK  SUPPLY 

bottle  epidemics  are  not  rare  by  any  means.  What  the  danger  from 
this  source  is  should  be  clearly  understood.  Not  every  can  or  bottle 
that  goes  into  premises  harboring  contagion  is  infected.  In  fact  probably 
but  few  of  them  are  and  those  are  the  ones  with  which  the  victim  of  the 
disease  or  perhaps  his  attendants  come  into  direct  or  indirect  contact; 
the  others  escape  infection.  Perhaps  the  likelihood  of  infection  is  greatest 
where  the  patient  is  coming  down  with  the  disease  or  is  convalescing 
for  in  these  stages  he  is  about  and  helping  himself.  However,  if  bottles 
are  handled  by  the  patient's  nurse  or  are  carried  into  the  sickroom  there 
is  danger  throughout  the  illness.  There  are  but  two  safe  courses  for 
the  milkman  to  pursue.  The  better  is  to  insist  on  leaving  no  bottles 
during  the  illness  but  instead  to  pour  the  milk  into  a  covered  container 
furnished  by  the  householder.  The  other  way  is  to  leave  bottles  as 
usual  but  to  carry  none  away  till  the  sickness  is  over  and  then  to  make  a 
special  trip  for  them  and  disinfect  them  thoroughly  by  themselves. 
The  objections  to  this  way  of  doing  are  twofold,  namely:  (1)  that  many 
bottles  accumulate  at  the  residence,  to  the  annoyance  of  the  house- 
holder, and  to  the  cost  of  the  dairyman ;  and  (2)  that  there  is  some  danger 
in  returning  infected  bottles  to  the  dairy.  The  board  of  health  of  Mont- 
clair,  N.  J.,  has  met  the  danger  of  infected  bottles  in  a  commendable  way 
by  informing  the  dairymen  concerned,  of  the  presence  of  contagion  as  soon 
as  the  board  itself  is  notified  by  the  attending  physician  of  the  case.  It  is 
recognized  that  this  mitigates  the  evil  rather  than  prevents  it  for  in  the 
prodromal  stage,  while  the  case  is  under  observation  by  the  physician 
it  may  be  infectious  and  do  damage.  However,  this  notification  protects 
both  dairymen  and  the  public  to  a  considerable  extent,  and  it  is  to  be 
regretted  that  it  has  not  been  generally  adopted. 

As  an  example  of  an  epidemic,  caused  by  infected  cans  that  at 
Savannah,  Ga.,  in  1907,  will  suffice.  Sixty-three  of  the  95  cases  appeared 
on  the  route  of  a  wholesaler  who  supplied,  among  others,  a  depot  that 
was  located  in  a  bake  shop  over  which  there  was  a  case  of  typhoid  fever. 
The  cans  were  returned  unsterilized  and  so  used,  to  supply  other  cus- 
tomers. 

Of  late  years  many  epidemics  have  been  traced  to  the  use  of  infected 
bottles.  In  Montclair,  N.  J.,  in  1901,  cases  of  diphtheria  suddenly 
appeared  on  one  of  the  most  prominent  dairy  routes  of  the  town.  Cul- 
tures were  taken  from  the  throats  of  the  entire  dairy  crew  and  two  of 
them  proved  positive.  The  crew  was  isolated  and  delivery  of  the  milk 
suspended  for  3  days.  New  cases  ceased  to  appear  within  2  days  after 
the  dairy  was  closed.  In  all  there  were  57  cases,  22  in  Montclair  and 
35  in  neighboring  towns.  The  crew  remained  isolated  for  3  weeks  during 
which  period  virulent  bacilli  were  found  at  one  time  or  another  in  the 
throats  of  17  of  the  men.  At  no  time  were  any  of  the  men  ill  or  did  they 
exhibit  clinical  symptoms  other  than  a  reddening  of  the  throats  of  the 


DISEASES  COMMUNICABLE  IN  MILK  83 

two  men  that  were  first  picked  out.  It  seems  that  it  was  the  custom  of 
the  dairy  to  leave  bottles  at  homes  during  the  course  of  contagious  dis- 
eases and  at  the  removal  of  quarantine  to  carry  them  back  to  the  dairy 
and  sterilize  them  before  using  them.  In  winter  the  breakage  was 
considerable  and  so  to  avoid  this  loss  the  bottles  were  kept  in  a  safe  place 
till  the  advent  of  warm  weather  when  the  whole  batch  was  sterilized  at 
once.  It  transpired  that  about  1  week  prior  to  the  appearance  of  the  first 
case  of  diphtheria  in  Montclair  the  two  men  who  were  first  removed 
from  the  crew  were  sent  down  to  a  shanty  to  boil  out  the  winter's  stock 
of  infected  bottles.  They  finished  the  job,  returned  to  their  quarters 
and  were  milking  as  usual  that  evening;  so  the  explanation  of  the  out- 
break is  manifest. 

In  December,  1902,  in  Montclair,  N.  J.,  the  author  investigated  a 
typhoid  fever  outbreak  that  appeared  on  the  route  of  a  dairyman  whose 
brother  produced  the  bulk  of  the  suspected  milk  but  who  also  handled  a 
small  amount  that  he  purchased  from  a  wholesaler  whose  supply  came 
from  10  different  farms.  Searching  investigation  at  all  of  the  11  farms 
under  suspicion  failed  to  reveal  any  cases  of  typhoid  fever  thereon  or 
that  any  employees  had  quit  them  for  any  reason.  The  dairyman 
volunteered  the  information  that  he  believed  that  it  was  the  wholesaler's 
milk  that  was  infected  for  the  disease  was  wholly  confined  to  this  pint- 
bottle  customers  for  which  trade  the  wholesaler's  milk  was  solely  used, 
the  quart-bottle  customers  being  entirely  supplied  from  his  brothers 
farm.  This  led  to  a  close  reexamination  of  the  wholesaler's  business 
but  no  apparent  cause  of  infection  was  discovered  nor  were  there  any 
cases  of  typhoid  fever  found  on  a  retail  route  run  by  the  wholesaler  in 
Newark,  whereas  inquiry  in  Bloomfield  showed  that  the  dairyman  had 
cases  on  his  delivery  route  there.  These  facts,  coupled  with  the  admis- 
sion on  the  part  of  the  dairyman  that  he  had  not  sterilized  his  bottles 
thoroughly,  led  to  the  conclusion  that  the  epidemic  was  caused  by 
infected  bottles  and  to  the  withdrawal  of  the  supply  from  town.  The 
outbreak  which  at  the  time  was  on  the  increase  stopped  within  2  weeks 
thereafter.  The  reason  why  not  a  single  quart-bottle  customer  in  either 
of  the  two  affected  towns  developed  the  disease  was  a  mystery.  It  was 
ultimately  solved  by  the  discovery  that  a  case  of  typhoid  fever  had  come 
to  Montclair  from  New  York  City  and  pending  removal  to  the  local 
hospital  had  remained  in  a  household  where  the  dairyman  daily  left 
and  took  away  three  pint  bottles.  The  bottles  that  were  removed  were 
not  sterilized  but  merely  washed  out,  filled  and  served  to  other  families. 
Had  the  case  been  reported  to  the  board  of  health  as  the  law  required  or 
had  the  dairyman  faithfully  sterilized  the  bottles  the  epidemic  never 
would  have  occurred. 

Infection  of  Milk  in  Delivery. — Milk  may  be  infected  on  the  delivery 
route.     At  Clifton,  a  suburb  of  Cincinnati,  Ohio,  in  1906,  the  milk  of  a 


84  CITY  MILK  SUPPLY 

small  dairy  was  delivered  by  a  boy  who  had  a  "sore  throat"  but  who  was 
not  under  a  physician's  care.  Thirty-six  cases  of  diphtheria  appeared 
on  the  route.  Many  incidents  of  epidemiological  significance  pointed 
to  the  milk  and  the  boy  as  the  source  of  infection.  In  Vermont,  in  1902, 
six  cases  of  diphtheria  appeared  on  the  route  of  a  dairy  whose  milk  was 
delivered  by  dipping  from  a  large  can  by  a  boy  who  had  "sore  throat" 
but  from  which  diphtheria  bacilli  were  later  isolated.  Cases  developed 
in  houses  where  he  left  the  milk  but  in  others  on  the  same  street  where 
he  did  not,  there  were  none.  In  Chester,  Mass.,  nine  cases  of  typhoid 
fever  appeared  on  the  route  of  a  dairy  of  which  the  wagon  driver  had 
just  recovered  from  the  disease,  the  epidemic  stopped  on  his  dismissal. 

Infection  of  Milk  after  Delivery. — Milk  may  also  be  infected  in  shops 
where  it  is  kept  for  sale;  this  is  especially  likely  to  occur  if  it  is  dispensed 
from  cans  or  diptanks.  At  Hamar,  Norway,  in  1900,  there  were  42 
cases  of  typhoid  fever  among  the  customers  of  a  shop  where  the  pro- 
prietor and  his  wife  had  the  disease;  the  latter  tended  store  while  still  ill. 
Savage  records  an  outbreak  of  scarlet  fever  reported  by  Robertson  in 
1901.  Forty  cases  were  traced  to  a  milk  shop  that  communicated  by  a 
short  passage  with  a  house  wherein  was  a  woman  suffering  from  an  un- 
recognized case  of  scarlet  fever.  On  the  removal  of  the  woman  to  a 
hospital  the  epidemic  waned. 

Milk  is  sometimes  infected  after  delivery  in  homes,  restaurants  and 
hotels.  In  private  homes  the  infection  is  most  likely  to  occur  when  there 
is  contagion  in  the  household  but  at  other  times  it  may  be  brought 
about  by  servants  and  others,  who  are  carriers.  In  any  event  the  cases 
are  usually  restricted  to  the  members  of  the  family  and  to  friends.  From 
milk  infection  in  restaurants  and  hotels  widespread  infection  may  result. 
The  sudden  appearance  in  Boston,  Mass.,  of  37  cases  of  typhoid  fever 
about  Sept.  21,  1909,  led  to  the  inquiry  into  conditions  at  a  hotel  in 
Jefferson,  Mass.,  because  all  of  the  patients  told  of  having  spent  Labor 
Day,  Sept.  6,  there.  After  some  investigation  interest  centered  on  a 
waitress  who  in  a  very  tired  condition,  left  the  hotel  Sept.  9,  and  who 
called  a  physician  on  the  15th.  She  gave  a  positive  Widal  reaction  on 
the  22nd,  which  showed  that  her  case  antedated  the  cases  among  the 
guests  by  1  or  2  weeks.  The  bulk  of  the  milk  used  at  the  hotel  arrived 
at  8  a.m.  part  being  used  at  once  and  part  being  kept  over  night  and 
served  the  next  morning.  When  the  hotel  was  crowded  the  capacity 
of  the  ice  chest  was  overtaxed  and  consequently  the  milk  was  insufficiently 
refrigerated.  The  milk  was  ladled  out  of  the  cans  into  pitchers  by  maids, 
who  filled  the  glasses  from  them;  often  the  dippers  dropped  back  into  the 
cans.  The  waitress  who  was  ill  was  fond  of  milk  and  often  made  her 
supper  of  milk  and  cakes,  helping  herself  from  the  cans.  It  is  believed 
that  on  Labor  Day  eve  she  infected  the  milk  and  as  it  was  not  properly 
iced  at  that  time  there  was  an  abundant  growth  of  typhoid  germs  in  the 


DISEASES  COMMUNICABLE  IN  MILK  85 

milk  next  morning.  In  all  there  were  59  cases  in  52  households  that  were 
located  in  10  different  cities  and  every  one  of  the  patients  is  known  to  have 
used  the  milk. 

Impossibility  of  Protecting  the  Milk  from  Infection. — The  recital  of 
these  specific  instances  of  milk  infection  makes  it  obvious  that  no  pro- 
ducer or  purveyor  of  raw  milk  can  be  absolutely  certain  that  the  article 
that  he  is  marketing  is  free  from  contagion.  Pestilence  in  invisible  form 
and  devious  ways  sneaks  into  the  dairy  so  unobtrusively  that  even  the 
most  careful  and  observant  are  unaware  that  anything  is  wrong  till  the 
blow  falls.  There  exist  three  types  of  cases,  or  stages  of  communicable 
disease  that  may  at  any  time  bring  infection  into  the  dairy,  and  which 
it  is  impossible  to  guard  against. 

First  are  cases  in  the  prodromal  stage  particularly  of  typhoid  fever 
where  germs  are  thrown  off  from  the  body  before  the  victim  feels  the 
warning  pains  of  illness. 

Second  are  the  ambulatory  cases  where  the  sick  continue  at  their 
usual  occupation,  though  feeling  excessively  tired,  mean  or  distressed. 
These  cases  are  apt  to  do  a  great  deal  of  harm  for  they  may  distribute 
the  virus  of  their  disease  for  a  considerable  period  and  in  many  places 
before  they  are  discovered.  Indeed,  some  never  are  found  out  and  these 
constitute  the  "  missed "  cases  which  are  decidedly  to  be  reckoned  with 
in  preventive  medicine.  The  epidemic  of  scarlet  fever  that  occurred 
in  Boston,  Mass.,  in  1910,  was  attributed  to  a  missed  case  on  some  one 
of  the  250  farms  that  supplied  the  dealer  involved.  There  were  842 
cases  in  Boston  and  its  suburbs.  Of  409  cases  in  the  city  proper  286, 
or  approximately  70  per  cent.,  were  on  the  route  of  this  one  dealer.  It 
was  on  April  25,  that  the  milk  was  suspected  and  on  that  date  orders 
were  given  to  pasteurize  it  and  sterilize  the  utensils.  On  April  27, 
pasteurization  was  begun,  on  the  29th  reported  cases  reached  a  maximum 
of  123  reported  new  cases.  Thereafter  the  epidemic  declined  and  died 
out  on  May  7. 

Third  are  the  carrier  cases.  There  are  the  acute  carriers,  persons 
that  have  convalesced  but  still  give  off  the  germs  of  the  disease  that 
affected  them.  In  1901,  in  Beverly,  Salem  and  Bakers  Island,  there 
occurred  suddenly  60  cases  of  scarlet  fever  among  the  customers  of  a 
single  dealer.  The  trouble  was  traced  to  one  of  the  farms  whence  his 
supply  came,  whereon  a  convalescent  milker  had  infected  the  milk. 
Chronic  carriers  present  a  more  serious  problem.  They  are  those  that 
have  been  ill  of  infection  made  an  apparently  complete  recovery  but  for 
months  or  years  thereafter  continue  to  scatter  the  specific  germs  of  their 
malady.  It  is  estimated  that  about  2  per  cent,  of  all  typhoid  fever 
patients  continue  to  discharge  the  bacilli  in  the  feces  and  urine  for  an 
indefinite  period  after  recovery.  Of  the  many  instances  that  might  be 
cited  to  illustrate  the  infection  of  a  milk  supply  by  a  chronic  carrier,  one 


86  CITY  MILK  SUPPLY 

that  was  discovered  by  Boldman  and  Noble  will  suffice.  In  August, 
1909,  there  was  an  outbreak  of  typhoid  fever  in  that  part  of  New  York 
City  that  lies  north  of  40th  Street.  There  were  380  cases  above  the 
normal  for  the  district  and  a  certain  milk  supply  that  was  common  to  all 
was  shut  off.  The  infected  milk  was  found  to  come  from  Camden,  N.  J., 
where  it  was  found  there  had  been  a  case  of  typhoid  fever  on  a  farm  that 
was  not  a  patron  of  the  creamery  that  shipped  the  milk  under  suspicion. 
Inquiry  developed  the  fact  that  every  year  there  were  in  town  14  or  15 
cases  of  " Camden  fever"  which  was  in  reality  typhoid  fever.  This  is 
at  the  rate  of  50  or  60  cases  per  10,000  of  population;  an  excellent  illus- 
tration of  the  well-known  fact  that  a  few  cases  in  a  small  town  may  be 
the  equivalent  of  many  in  a  metropolitan  center.  At  the  dairy  where 
the  typhoid  fever  was,  it  was  found  that  the  owner  had  the  disease  in 
1864,  and  that  in  his  family  since  that  time  there  had  been  four  cases  of 
typhoid  fever  and  three  of  "slow  fever"  resembling  typhoid.  On  examina- 
tion of  the  stools  of  the  entire  family  it  was  found  that  those  of  the  dairy- 
man himself  who  had  the  disease  46  years  before  yielded  typhoid  bacilli 
in  practically  pure  cultures  on  the  medium  in  which  platings  were  made. 
Connection  of  this  man  with  the  New  York  epidemic  was  established  when 
it  was  found  out  that  he  ran  one  of  the  three  local  milk  routes  in  Camden 
and  was  in  the  habit  of  turning  over  his  surplus  milk  to  his  son-in-law 
who  added  it  to  his  own  and  delivered  it  to  the  creamery  of  which  he  was 
a  patron.  "Thus  the  prevalence  of  'Camden  fever'  in  Camden  and 
typhoid  fever  in  New  York  were  both  explained."  With  the  shutting  off 
of  the  infected  milk  typhoid  fever  in  New  York  City  returned  to  normal. 

The  infection  of  milk  by  temporary  bacillus  carriers  is  perhaps  most 
often  accomplished  by  those  harboring  diphtheria  germs.  It  is  estimated 
that  1  per  cent,  of  the  urban  population  carries  diphtheria-like  organisms. 
The  nurses  of  diptheria  patients  are  particularly  prone  to  become  tem- 
porary carriers.  The  men  in  Montclair  whose  throats  probably  became 
infected  with  diphtheria  germs  while  they  were  sterilizing  the  bottles 
afford  a  good  example  of  a  temporary  carrier  infecting  a  milk  supply. 
There  are  also  acute  carriers  those  who  having  had  contagious  disease 
continue  to  carry  the  germs  for  a  brief  period.  Such  persons  may  also 
infect  the  milk  supply. 

Characteristics  of  Milk-borne  Epidemics. — Milk-borne  epidemics 
possess  certain  characteristics  which  should  be  remembered  whenever 
it  is  sought  to  determine  the  source  of  an  outbreak  of  contagion  of  un- 
known origin.  There  are  two  sorts  of  milk-engendered  epidemics;  those 
which  burst  on  a  community  with  explosive  violence,  and  those  which 
smolder  on  without  exciting  comment.  Of  the  former  type  the 
epidemic  of  typhoid  fever  at  Stamford,  Conn.,  in  1895,  is  an  example. 
There  were  386  cases  and  22  deaths  in  the  period  from  April  15  to  May 
28.  No  less  than  176  persons  were  stricken  in  the  first  week.  Such 


DISEASES  COMMUNICABLE  IN  MILK  87 

outbreaks  rouse  the  community  to  instant  action  and  something  usually 
is  done  which  checks  the  outbreak  when  it  is  on  a  rising  tide.  As  an 
instance  of  the  other  kind  of  epidemic  that  at  Belleville,  111.,  may  be 
cited.  In  the  7  months  from  July,  1911,  to  January,  1912,  there  were 

23  cases  of  typhoid  fever  which  if  the  same  distribution  of  cases  had  con- 
tinued throughout  the  year  would  have  been  equivalent  to  a  typhoid 
morbidity  rate  of  practically  14  per  10,000  of  population  and  which  is 
not  excessive.     As  a  matter  of  fact  the  cases  being  distributed  in  the 
practice  of  several  physicians  and  among  people  who  as  a  whole  were 
unacquainted  with  each  other  attracted  absolutely  no  attention  but  when 

24  cases  appeared  in  February  and  41  in  March  bringing  the  rate  up  to 
nearly  56  there  was  alarm  at  once.     It  was  found  that  over  85  per  cent. 
of  all  the  cases  were  due  to  the  milk  of  a  single  dairy  which  all  this  time 
had  been  kept  infected  by  a  carrier  who  only  at  irregular  intervals  came 
into  contact  with  the  milk  supply  and  infected  it.     The  increased  number 
of  cases  in  February  and  March  was  in  part  explainable  by  the  fact  that 
during  these  months  the  contact  of  the  carrier  with  the  route  was  more 
regular.     Had    typhoid  fever  been  a  reportable  disease  in  Illinois  at  that 
time  suspicion  would  probably  have  fallen  on  the  dairy  in  question  sooner. 
Hill  tells  of  the  experience  of  North  Branch,  Minn.,  where  one  of  the 
physicians  pointed  out  that  in  his  17  years  of  practice  during  the  first 
12  there  was  no  typhoid  fever  but  that  in  the  last  5,  native  cases  of  un- 
known origin  had  not  been  infrequent.     Acting  on  this  information  a 
list  of  21  cases  of  typhoid  fever  that  had  appeared  in  the  town  in  the  last 
5  years  was  made  and  inquiry  showed  that  17  of  the  patients  were  regular 
customers  of  a  dairyman  who  had  come  to  town  5  years  before,  besides 
which,  two  were  occasional  customers  and  two  more  might  have  been. 
It  developed  that  the  wife  of  the  dairyman  who  had  typhoid  fever  22 
years  before  washed  the  cans.     This  woman  showed  a  positive  Widal 
reaction  but  typhoid  bacilli  were  not  isolated  from  her  stools.     She  was 
forbidden  to  have  anything  to  do  with  the  dairy  and  the  proprietor  was 
told  that  if  another  primary  case  of  typhoid  fever  appeared  among  his 
customers  the  dairy  would  be  closed  up.     Rumors  of  this  were  hinted 
about  the  town  so  that  trade  fell  off  and  the  family  moved  away,  after 
which  there  was  no  more  typhoid  fever.     Thus  all  the  cases  of  typhoid 
fever  in  North  Branch  were  due  to  the  occasional  infection  of  the  milk 
supply. 

The  explosive  sort  of  epidemic  is  usually  thought  of  as  being  typical 
of  milk-borne  outbreaks,  but  the  smoldering  kind  must  be  very  common 
especially  in  communities  that  lack  a  modern  health  department  and 
laws  compelling  compulsory  notification  of  contagious  disease.  No 
doubt  too,  much  of  the  sporadic  and  residual  typhoid  that  persists  in  our 
large  cities,  were  all  the  facts  known,  might  be  traced  to  occasional  or 
intermittent  infection  of  the  food  supply  by  carriers  and  others. 


88  CITY  MILK  SUPPLY 

Milk-borne  epidemics  follow  the  delivery  wagon.  This  is  most 
plainly  seen  in  small  routes  supplied  from  a  very  few  farms;  in  large 
routes  where  all  the  milk  is  not  mixed  together  the  connection  between 
milk  delivery  and  contagion  may  be  less  obvious,  but  usually  patient 
inquiry  at  the  dairy  and  along  the  route  will  develop  such  a  relationship 
if  it  actually  exists. 

Great  care  must  be  taken  not  to  unjustly  impute  an  epidemic  to  a 
milk  supply.  The  mere  fact  that  the  number  of  cases  is  large,  while 
sufficient  to  arouse  suspicion,  does  not  warrant  the  conclusion  that  the 
supply  is  actually  responsible  for  an  outbreak.  The  percentage  that 
the  milk  served  by  the  suspected  dairy  forms  of  all  milk  in  the  district 
under  scrutiny  must  be  determined,  as  well  as  the  number  of  cases  on 
the  route.  A  dairyman  who  serves  50  per  cent,  of  the  families  in  a  dis- 
trict may  be  expected  to  have  among  his  customers  a  large  number  of 
cases  of  a  contagion  that  breaks  out  therein.  Harrington  instances  an 
outbreak  of  scarlet  fever  in  Boston  in  1897  that  was  wrongfully  attributed 
by  the  public  to  a  milk  dealer  who  delivered  to  most  of  the  stricken  families. 
Careful  investigation  by  the  health  department  showed  that  the  first  case 
was  that  of  a  child  who  did  not  have  the  accused  milk  and  that  the  epi- 
demic was  spread  by  contact  from  this  first  case.  Pease  tells  of  an  epi- 
demic where  50  per  cent,  of  the  cases  were  customers  of  a  single  milk  dealer 
who  was  forthwith  accused  of  causing  the  outbreak  but  who  was  cleared 
of  responsibility,  upon  it  being  shown  that  an  infected  water  supply 
was  really  to  blame,  it  being  simply  a  coincidence  that  the  dealer  supplied 
50  per  cent,  of  the  cases. 

In  milk-borne  epidemics  it  so  often  happens  that  more  than  one  case 
appears  at  the  same  time  in  a  single  household  that  such  occurrences 
warrant  the  suspicion  that  the  milk  supply  may  be  involved. 

It  frequently  happens  also,  that  the  better-class  houses  are  invaded 
for  the  reason  that  the  occupants  can  best  afford  milk  and  so  use  it  more 
freely  than  do  the  poorer  classes.  Those  households  using  the  most  milk 
are  most  frequently  attacked  and  show  the  greatest  percentage  of  cases. 

Likewise,  there  is  a  special  incidence  among  milk  drinkers;  often  a 
member  of  a  household  who  abhors  milk  will  escape  infection,  whereas 
those  that  drink  milk  freely  are  attacked. 

The  age  and  sex  of  the  victims  is  frequently  indicative  that  milk  is 
responsible  for  an  outbreak.  If  the  sufferers  are  mostly  women,  young 
people  and  children,  the  epidemic  is  likely  to  prove  to  be  milk-borne, 
for  they  consume  milk  more  freely  than  adult  males.  Judgment  must 
be  exercised  in  applying  this  rule,  for  in  some  communities  children  form 
a  considerable  part  of  the  population  while  in  others  they  are  conspicu- 
ously absent. 

As  to  the  character  of  milk-borne  outbreaks  there  is  some  evidence 
to  indicate  that  the  infections  may  be  more  benign  than  when  they  origi- 


DISEASES  COMMUNICABLE  IN  MILK  89 

nate  from  direct  contact  or  in  other  ways.  Savage  says  that  in  some 
epidemics  of  scarlet  fever  spread  by  milk  that  a  number  of  cases  have 
shown  so  few  symptoms  of  the  disease  that  apart  from  their  relationship 
to  other  and  undoubted  cases  a  certain  diagnosis  of  scarlet  fever  would 
not  be  possible,  and  quotes  Newsholme  on  the  scarlet  fever  epidemic  at 
Brighton,  England,  in  1902  and  Buchanan  on  the  outbreak  at  Kensington, 
England,  in  1875.  He  points  out  that  in  the  acute  infectious  diseases 
the  smallest  percentage  invasion  of  households  is  met  with  in  scarlet 
fever  outbreaks  and  says  that  it  would  probably  be  higher  if  the  atypical 
cases,  mainly  or  exclusively  with  symptoms  of  sore  throat,  were  included. 
Savage  also  thinks  contact  cases  less  frequent  in  milk-borne  outbreaks 
than  in  those  having  other  origins. 

Touching  milk-borne  typhoid  fever,  Newman  says  that  the  incubation 
period  is  shortened,  attacks  are  often  mild,  contact  infectivity  reduced 
and  the  mortality  rate  lower  than  usual. 

Injury  Done  by  Milk-borne  Epidemics. — The  damage  done  by  the 
contagion  that  is  spread  by  milk  cannot  be  accurately  gaged.  The 
amount  of  milk  that  becomes  infected  as  compared  with  that  produced 
is  very  small  and  were  it  to  be  considered  in  that  light  only  could  be 
disregarded  but  every  epidemic  stands  for  a  definite  amount  of  human 
misery  and  loss  which  added  to  that  sustained  in  epidemics  that  have 
gone  before  makes  a  sum  that  compels  "attention.  Boston,  Mass., 
despite  the  fact  it  has  a  very  fair  milk  supply,  has  had  the  following  record 
of  milk-borne  contagion: 

Cases 
1907,  diphtheria 72 

1907,  scarlet  fever 717 

1908,  typhoid  fever . 400 

1910,  scarlet  fever 842 

1911,  septic  sore  throat 2,064 


4,095 

Such  a  series  of  epidemics  is  unusual  but  in  almost  every  community 
where  raw  milk  is  bought  and  sold  something  of  the  kind  is  going  on,  so 
that  the  situation  should  be  frankly  faced  and  dealt  with,  without  either 
minimizing  the  danger  or  exaggerating  it. 

The  loss  that  contagion  causes  is  felt  all  along  the  line  from  the 
consumer's  home  to  the  farm.  To  begin  with  there  is  the  anguish  of 
the  stricken  family  and  the  sufferings  of  the  victims.  A  10  days'  illness 
is  succeeded  by  longer  convalescence  during  which  time  bills  for  medi- 
cines, the  nurse  and  the  doctor  accumulate,  and  if  death  ensues  the 
expenses  of  the  funeral  are  added.  If  the  wage-earner  contracts  the 
disease  his  earning  power  for  the  time  being  is  gone.  So  that  advent  of 
contagion  in  a  home  is  serious  and  may  even  bring  a  family  from  a  self- 
sustaining  condition  to  a  dependent  one.  The  retailer  is  likely  to  suffer 


90  CITY  MILK  SUPPLY 

severe  loss  from  an  epidemic.  At  the  first  rumors  of  trouble  of  this  kind 
customers  turn  to  other  dealers  and  there  consequently  results  a 
contraction  in  business  that  is  more  or  less  permanent,  depending  some- 
what on  the  quality  of  the  milk  that  has  been  delivered  by  the  dealer 
and  on  his  standing  with  his  trade.  Most  retailers  have  contracts  with 
farmers  that  hold  for  some  months  for  the  delivery  of  a  certain  amount 
of  milk  daily.  So,  when  shrinkage  in  the  trade  takes  place,  the  milk 
keeps  coming  regardless  of  the  fact  that  there  is  no  market  for  it.  There- 
fore, it  has  to  be  manufactured  into  butter  or  cheese  usually  with  attend- 
ant loss.  If  the  milk  is  infected  on  the  farm  the  supply  is  usually  shut 
off  at  once  which  is  likely  to  mean  severe  contraction  of  the  retailer's 
supply  and  complete  loss  to  the  farmer,  although  some  contractors  deem 
it  good  policy  to  pay  something  for  the  milk. 

Control  of  Milk-borne  Diseases. — In  the  United  States  responsi- 
bility for  the  control  of  contagious  disease  is  placed  on  the  local  or  on  the 
State  health  department.  Something  can  be  accomplished  by  inspections 
of  the  premises  whereon  the  milk  is  produced  or  sold.  Polluted  water 
supplies  can  be  eliminated;  insanitary  privies  cleaned  up;  screening 
against  flies  can  be  encouraged  and  wholesome  conditions  of  living  can 
be  fostered.  Where  milk  is  sold  in  stores  the  same  sort  of  measures 
should  be  applied  and  in  addition  the  sale  of  milk  from  rooms  that  are 
in  part  occupied  by  the  family  should  be  forbidden. 

Departmental  records  should  be  kept  in  such  a  way  as  to  show  the 
relation  of  milk  supplies  to  communicable  disease;  the  thing  vital  to 
the  success  of  doing  this,  is  to  get  all  cases  promptly  reported.  When 
this  is  done  and  the  cases  marked  up  on  the  dairy  routes  which  the 
victims  patronize  it  is  often  possible  to  detect  an  epidemic  at  its  inception 
and  to  institute  measures  to  check  it.  As  has  been  already  said  some 
help  is  given  by  a  system  of  notification  warning  dairymen  of  the  appear- 
ance of  contagion  in  the  household. 

However,  all  such  measures  are  only  helpful  in  reducing  the  opportu- 
nities of  infection.  Once,  it  was  hoped  that  by  thorough  inspection  of 
dairies,  strict  quarantine  and  similar  measures  to  reduce  danger. of  infec- 
tion of  milk  supplies  to  an  all  but  negligible  minimum  but  better  knowl- 
edge of  the  modes  of  transmission  of  contagion,  of  carriers,  missed 
cases,  bottle  infections,  etc.,  have  shown  that  it  is  a  delusion  to  cherish 
such  a  hope.  In  its  place  has  been  substituted  faith  in  pasteurization 
by  the  " holder"  process.  It  has  been  proven  that  the  germs  of  disease 
in  milk  are  killed  by  an  exposure  of  140°F.  for  %  hr.  so  that  if  the  process 
is  properly  protected  by  thorough  inspection,  the  safety  of  the  milk  can 
be  guaranteed. 

Sources 

MOORE,  "Bovine  Tuberculosis  and  Its  Control,"  1913. 
MELVIN,  "Tuberculosis,"  Am.  Vet.  Rev.,  vol.  34,  p.  250,  1908. 


DISEASES  COMMUNICABLE  IN  MILK  91 

SEDGWICK  and  BATCHELDER,  "A  Bacteriological  Examination  of  the  Boston  Milk 

Supply,"  Boston  Med.  and  Surg.  Jour.,  vol.  126,  p.  25,  1892. 
Bureau  of  Animal  Industry,  U.  S.  Dept.  Ag.,  "The  Effect  of  Certain  Diseases  of  Cattle 

upon  the  Milk  Supply,"  reprint   from  the  24th  Annual  Report,   1907. 
BRISCOE  and  MACNEAL,  "Tuberculosis  of  Farm  Animals,"  Bull.  149,  Univ.  111.  Ag. 

Expt.  Sta.,  1911. 
HAYDEN,  "Tuberculosis  in  the  University  Dairy  Herd,"  Bull.   162,  Univ.  111.  Ag. 

Expt.  Sta.,  1913. 
HARING  and  BELL,  "The   Intradermal  Test  for  Tuberculosis  in  Cattle  and  Hogs," 

Bull.  243,  Cal.  College  Ag.  Expt.  Sta.,  1914. 
HASTINGS,  "What  Has  Been  Done  with  the  Tuberculin  Test  in  Wisconsin,"  Bull.  243, 

Univ.  Wis.  Ag.  Expt.  Sta.,  1914. 
GILLIE,  Report  of  the  Committee  on  Bovine  Tuberculosis,  2d  Annual  Report  of  the 

International  Dairy  and  Milk  Inspectors,  p.  45,  1913. 

CHRISMAN,  "Tuberculin  Testing  of  Cattle,"  Bull  N.  C.  Dept.  Ag.,  vol.  33,  No.  7. 
DUNNE,  "Danish  Investigations  Showing  How  Tubercular  Fowls  Infect  Pigs,"  Jour. 

Board  Ag.,  vol.  22,   No.  1,  April,  1915. 
CAMPBELL,  "Tubercle  Bacilli  in  Market  Milk,  Philadelphia,"  26th  Annual  Report, 

Bureau  Animal  Industry,  U.  S.  Dept.  Ag.,  pp.  164-177,  1909. 
GOLER  and  EILINGER,  "Results  Obtained  by  Tuberculin  Testing  a  City's  Retail  Milk 

Supply,"  Trans.  1st  Annual  Meeting  of  the  American  Association  for  Study  and 

Prevention  of  Infant  Mortality,  November,  1910. 
WELLS,  13th  Annual  Report  of  the  Board  of  Health  of  the  Town  of  Montclair,  N.  H., 

p.  46,  1907. 
POPE,  "Practical  Methods  for  Disinfecting  Stables,"  Farmer's  Bull.  480,  U.  S.  Dept. 

Ag>7  1912. 

DORSET,  "Some  Common  Disinfectants,"  Farmer's  Bull.  345,  U.  S.  Dept.  Ag.,  1911. 
FERENBAUGH,  "Endemic  Mediterranean  Fever  in  Southwest  Texas,"  Jour.  A.  M.  A., 

vol.  57,  No.  9,  pp.  730-731,  1911. 
GENTRY  and  FERENBAUGH,  "Endemic  Malta  Fever  in  Texas  with  Isolation  of  M. 

melitensis  from  Two  Patients,"  Jour.  A.  M.  A.,  vol.  57,  No.  11,  p.  889,  1911. 
YOUNT  and  LOONEY,  "Malta  Fever  in  Arizona,"  South  Cal.  Pract.,  1912. 
RAVENEL,  "Anthrax,"  Phila.  Med.  Jour.,  April,  22,  1899. 

NEALE,  "Anthrax,"  5th  to  9th  Annual  Reports  Del.  College  Ag.  Expt.  Sta.,  1892-97. 
RUSSELL,  "Anthrax,"  17th  Annual  Report,  Univ.- Wis.  Ag.  Expt.  Sta.,  1900. 
MACNEAL,  ''  Contagious  Abortion  of  Cows,"  Butt.  152,  Univ.  111.  Ag.  Expt.  Sta.,  1911. 
FABYAN,  "Contagious  Abortion  of  Cows,"  Jour.  Med.  Res.,  vol.  24,  No.  3,  1912  and 

vol.  28,  No.  1,  1913. 
WILLIAMS,  "Abortion  in  Pedigreed  Cattle,"  Hoard's  Dairyman,  vol.  51,  No.  13,  p, 

540  and  No.  14,  p.  582,  1916. 

Bureau  of  Animal  Industry,  U.  S.  Dept.  Ag.  "Bact.  abortus  in  Cow's  Milk,"  Circ.  198. 
HADLEY  and  BEACH,  "Diagnosis  of  Contagious  Abortion  by  the  Complement  Fixa- 
tion Test,"  Res.  Bull.  24,  Univ.  Wis.  Ag.  Expt.  Sta. 

GOOD,  "Contagious  Abortion  of  Cows  and  Mares,"  Bull.  165,  Ky.  Ag.  Expt.  Sta. 
COOLEDGE,   "Agglutination  Test  as  a  Means  of  Studying  Bact.  abortus  in  Milk," 

Jour.  Ag.  Res.,  vol.  5,  No.  19,  1916. 
SHROEDER,  "Pure  Milk  Production  and  the  Abortion  Bacillus,"  Am.  Vet.  Rev.,  vol. 

44,  pp.  467-475,  January,  1914. 
PARK  and  KRUMWIEDE,  "The  Relative  Importance  of  the  Bovine  and  Human  Types 

of  Tubercle  Bacilli  in  the  Different  Forms  of  Tuberculosis,"  Collected  Studies 

from  the  Research  Laboratory,  Department  of  Health  of  New  York  City,  vol. 

7,  pp.  88-92,  1912-1913. 


92  CITY  MILK  SUPPLY 

HESS,  "The  Subsequent  Health  of  Children  who  Drank  Milk  Containing  Tubercle 

Bacilli,"  Studies  from  the  Research  Laboratory  Department  of  Health,  New 

York  City,  vol.  6,  pp.  141-144,  1911. 
KOBER,  "Milk  in  Relation  to  the  Public  Health,"  Sen.  Doc.  441,  57th  Cong.,  First 

Session,  1902. 

SAVAGE,  "Milk  and  the  Public  Health,"  1912. 
Hygienic  Laboratory  Bull.  56,  "  Milk  in  Relation  to  the  Public  Health,"  U.  S.  Treasury 

Dept.,  1909. 

ROSENAU,  "Preventive  Medicine  and  Hygiene,"  1913. 
SUTTON  and  O'DONNELL,  "Foot-and-mouth  Disease,"  Jour.  A.  M.  A.,  vol.  66,  No.  14, 

pp.  947-949,  1916. 

ERNST,  MOHLER  and  EICHHORN,  "Milk  Hygiene,"  1914. 
LARSON  and  SEDGWICK,  "The  Complement-fixation  Reaction  of  the  Blood  of  Children 

and  Infants,  Using  B.  abortus  as  Antigen,"  Am.  Jour.  Diseases  of  Children,  vol. 

6,  No.  5,  pp.  326-333,  1913 

SEDGWICK,  LARSON  and  RAMSEY,  Further  Studies  on  the  Epidemic  Abortion  Reac- 
tions in  Children,"  Am.  Jour.  Diseases  of  Children,  vol  10,  No.  3,  pp.  197-200, 1915. 
NICOLL  and  PRATT,  "  Does  the  B.  abortus  Infect  Man  ?     Am.  Jour.  Diseases  of  Children, 

vol.  10,  No.  3,  1915. 
SHROEDER,  "The  Cause  and    Occurrence  of    Contagious  Abortion  in  Cattle,"  4th 

Annual  Report  of  the  International  Association  of  Dairy  and  Milk  Inspectors, 

pp.  139-145,  1915. 
COOLEDGE,  "Is  Bad.  abortus  (Bang)  Pathogenic  for  Human  Beings?     Jour.  Med. 

Res.,  vol.  34,  No.  3,  pp.  459-467,  July,  1916. 

WINSLOW,  "An  Outbreak  of  Tonsillitis  or  Septic  Sore  Throat  in  Eastern  Massachu- 
setts and  its  Relation  to  an  Infected  Milk  Supply,"  Jour.  Infect.  Diseases,  vol.  10, 

No.  1,  pp.  73-112,  1912. 
FROST,  STOKES  and  HACHTEL,  "A  Milk-borne  Outbreak  in  Baltimore,  Md.,  with  a 

Bacteriological  Study  of  the  Outbreak,"  Public  Health  Reports,  U.  S.  Treasury 

Dept.,  vol.  27,  No.  47,  pp.  889-1930,  1912. 
CAPPS  and  MILLER,  "The  Chicago  Epidemic  of  Streptococcus  Sore  Throat  and  its 

Relation  to  the  Milk  Supply,"  Jour.  A.  M.  A.,  vol.  58,  No.  24,  pp.  1848-1852, 

June  15,  1912. 
HEINEMAN,  "Epidemic  Sore  Throat  in   Chicago,"  Jour.  A.  M.  A.,  vol.  59,  No.  9, 

pp.  716-718,  1912. 
CAPPS,  "The  Role  of  Milk  in  the  Causation  of  the  Chicago  Epidemic  Sore  Throat," 

Jour.  A.  M.  A.,  vol.  59,  No.  19,  pp.  1715-1717,  1912. 
DAVIS  and  CAPPS,  "Experimental  Bovine  Mastitis  Produced  with  Streptococci  of 

Human  Origin,"  Jour.  Infect.  Diseases,  vol.  15,  No.  1,  pp.  135-140,  1914. 
NORTH,  WHITE  and  AVERT,  " Courtland-Homer  Outbreak  of  Septic  Sore  Throat," 

Jour.  Infect.  Diseases,  vol.  14,  No.  1,  pp.  124-143,  1914. 
COUES,  "Statistics  Regarding  the  Increased  Number  of  Throat  Infections  in  Boston," 

Am.  Jour.  Public  Health,  vol.  2,  No.  6,  1912. 
MANN,  "Septic  Sore  Throat  in  Concord,  N.  H.,"  Jour.  Infect.  Diseases,  vol.  12,  No. 

3,  pp.  481-497,  1913. 
RUEDIGER,  "A  Study  of  35  Strains  of  Streptococci  Isolated  from  Samples  of  Milk," 

Am.  Jour.  P,ublic  Health,  vol.  2,  No.  2,  pp.  107-109,  1912. 
SMITH  and  BROWN,   "A  Study  of  Streptococci  Isolated  from  Certain  Presumably 

Milk-borne  Epidemics  of  Tonsillitis  Occurring  in  Massachusetts  in  1913  to  1914," 

Jour.  Med.  Res.,  vol.  31,  No.  3,  pp.  455-501,  1915. 
KRUMWIEDE  and  VALENTINE,  "A  Bacteriological  Study  of  an  Epidemic  of  Septic 

Sore  Throat,"  Jour.  Med.  Res.,  vol.  33,  No.  2,  pp.  231-237,  1915. 


DISEASES  COMMUNICABLE  IN  MILK  93 

WINSLOW  and  HUBBARD,  "Epidemiology  and  Symptomatology  of  an  Outbreak  of 

Septic  Sore  Throat  in  Westchester  Co.,  New  York,"  Jour.  Infect.  Diseases,  vol. 

18,  No.  1,  1916,  pp.  106-117. 
KENDALL  and  SMITH,  "Diarrhea  in  Infants  Associated  with  the  Gas  Bacillus  in  Stools," 

Report  of  Boston  Floating  Hospital,  1910. 

SIMONDS,  "Gas  Bacillus  Infections,"  Jour.  Ind.  State  Med.  Soc.,  March,  1915. 
BARBER,  "Milk  Poisoning  Due  to  a  Type  of  Staphylococcus  albus,  Occurring  in  the 

Udder  of  a  Healthy  Cow,"  Philippine  Jour.  Sci.  B.  Trop.  Med.,  vol.  9,  No.  6, 

pp.  515-519,  1914. 
"An  Unusual  Outbreak  of  Milk  Poisoning,"  Public  Health  News,  Dept.  Health,  State 

of  New  Jersey.,  vol.  1,  No.  6,  pp.  102-105,  1916. 
MITCHELL,  "Viability  of  B.  typhosus  in  Ice  Cream,"  Jour.  A.  M.  A.,  vol.  65,  No.  21, 

November,  1915. 
HORTON,  "1st  Annual  Report,  Board  of  Health  of  Montclair,  N.  J.,  1895,  "Typhoid 

Fever  in  Ice  Cream." 
PARKER,  9th  Annual  Report,  Board  of  Health  of  Montclair,  N.  J.,  1903,  "Typhoid 

Fever." 
"Typhoid  Fever  at  Jefferson,  Mass."  Report  Massachusetts  State  Board  of  Health 

pp.  624-629,  1909. 
BOLDUAN,  "Typhoid  Fever  in  New  York  City,"  Monograph  Series  No.  3,  p.  43,  1912, 

Dept,  Health,  New  York  City. 
PARKER,  "Characteristics  of  Typhoid  Fever  Outbreaks,"  Proc.  4th  Meeting  of  the 

Illinois  Water  Supply  Association,  March,  1912. 
BOLDUAN  and  NOBLE,  "A  Typhoid  Bacillus-carrier  of  46  Years'  Standing,"  etc.,  Jour. 

A.  M.  A.,  vol.  58,  No.  1,  pp.  7-9,  1912. 
HILL,  "All  the  Typhoid  Fever  of  a  Community  for  5  Years  from  a  Carrier  through 

Milk,"  Am.  Jour.  Public  Health,  vol.  4,  No.  8,  pp.  667-673,  1914. 
PARKER,  "An  Outbreak  of  Typhoid  Fever  in  Belleville,  111.,"  Am.  Jour.  Public  Health, 

vol.  3,  No.  5,  pp.  486-491,  1913. 
HANSEN  and  PARKER,  "Typhoid  Fever  in  Rockford,  111.,"  Jour.  Infect.  Diseases,  vol. 

16,  No.  1,  pp.  1-23,  1915. 
KRUMWIEDE  and  NOBLE,  "The  Viability  of  the  Typhoid  Bacillus  in  Sour  Cream/' 

Am.  Jour.  Public  Health,  vol.  4,  No.  11,  pp.  106-108,  1914. 
HEINEMANN,   "Germicidal  Effect  of  Lactic  Acid,"  Jour.  Infect.  Diseases,  vol.  16, 

pp.  477-486,  1915. 

SEDGWICK,  "Principles  of  Sanitary  Science  and  the  Public  Health,"  1902. 
CURTIS,  "An  Apparent  Milk-borne  Outbreak  of  Paratyphoid,"  Am.  Jour.  Public 

Health,  vol.  3,  No.  12,  pp.  1,311-1,314,  1913. 
LEVINE  and  EBERSON,  "A  Milk-borne  Paratyphoid  Outbreak  at  Ames,  Iowa,"  Jour. 

Infect.  Diseases,  vol.  18,  No.  7,  pp.  143-150,  1916. 
"Scarlet  Fever  in  Boston,  Mass,"  39th  Annual  Report  of  the  Board  of  Health  of  the 

City  of  Boston,  pp.  3-6,  1910. 
LEIGHTON,  6th  and  7th  Annual  Reports  of  the  Board  of  Health  of  Montclair,  N.  J., 

1901,  "Diphtheria." 
CARPENTER,  "The  Distribution  of  Cases  Among  the  Several  Producers  in  Epidemics 

of  Non-milk-borne  Infectious  Diseases,"  Am.  Jour.  Public  Health,  vol.,  2  No.  4, 

pp.  296-299,  1912. 


CHAPTER  III 
DAIRY  CATTLE  AND  THE  DAIRY  FARM 

Origin  of  Domesticated  Cattle. — The  dairy  industry  of  the  United 
States  is  immensely  important.  A  vast  amount  of  capital  is  invested 
therein;  to  it  the  choicest  of  agricultural  lands  are  devoted  and  from  it 
an  army  of  men  get  employment,  but  the  gains  that  it  offers  are  not  easy. 
To  reap  them  requires  training  and  skill  of  a  high  order  backed  by  ex- 
perience. The  questions  that  assail  the  dairy  farmer  are  many;  they 
begin  with  the  cow  herself. 

The  origin  of  domesticated  cattle  has  not  been  certainly  determined 
but  two  wild  species  namely  Bos  primigenius  and  Bos  longifrons  seem 
to  have  been  particularly  important  in  their  evolution.  The  former  is 
known  to  us  by  old  paintings  that  are  believed  to  represent  the  animal 
and  by  skeletons.  It  persisted  until  the  early  part  of  the  seventeenth 
century  in  the  regions  of  the  upper  Duna  and  Dnieper  Rivers  and  in 
the  Carpathian  Mountains.  It  was  6  to  7  ft.  at  the  withers  and  10  to 
12  ft.  long  and  was  characterized  by  a  long  narrow  head. 

Bos  longifrons  is  believed  to  be  derived  from  Asiatic  species,  probably 
Bos  sondaicus.  It  seems  to  be  identical  with  the  marsh  cow  of  the  Lake 
Dwellers  and  its  earliest  and  most  typical  forms  are  found  on  the  northern 
shores  of  the  Mediterranean,  the  Alpine  region  and  the  Atlantic  coast 
of  western  Europe.  It  was  smaller  than  Bos  primigenius  with  shorter 
horns,  face  and  forehead. 

Keller  derives  the  European  cattle  from  two  distinct  races,  thus : 

1.  Those  of  Bos  primigenius  ancestry.     They  are  characterized  by 
a  long  narrow  head  and  include  the  English   Park  cattle,  the  North 
German,  Lowland,  Dutch,  Steppe,  Simmenthal  and  Freiburg  spotted 
breeds. 

2.  Those  of  Bos  sondaicus  ancestry.     They  are  characterized  by  a 
broad  short  head  and  include  the  Albanian,  Polish,  Hornless  Fjell  and 
Brown  Swiss  breeds  as  well  as  the  Channel  Island  and  English  cattle 
except  the  Longhorn  and  Scotch  Highland,  but  the  Shorthorn,  Ayrshire 
and  some  others,  early  received  an  admixture  of  Bos  primigenius  blood. 

Introduction  of  Cattle  into  America. — Cattle  are  not  native  to 
America.  The  first  were  brought  over  by  Columbus  on  his  second  voyage 
in  1493.  Later,  settlers  from  Spain  brought  cattle  to  the  West  India 
Islands  whence  they  were  carried  to  the  mainland  both  north  and  south 
of  the  Isthmus  of  Panama.  In  1525  cattle  were  carried  to  Vera  Cruz 

94 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  95 

where  they  multiplied  and  gave  rise  to  the  stock  later  known  to  breeders 
in  the  United  States  as  " Texas"  cattle.  Cattle  were  brought  to  New- 
Foundland  and  Nova  Scotia  in  1553  and  are  said  to  have  been  introduced 
to  Sable  Island  as  early  as  1508.  Importations  to  Canada  were  largely 
from  France,  particularly  from  Normandy  and  Brittany.  Many  cattle 
were  carried  to  Jamestown,  Va.  from  the  West  Indies  in  1610-11  and  Eng- 
lish breeds  were  also  introduced  there.  In  1624,  the  first  cattle  came 
into  Massachusetts  Bay.  Boston  imported  mostly  English  breeds,  the 
Devon  predominating.  Plymouth  brought  in  cattle  from  both  England 
and  Holland.  In  1624,  the  Dutch  settled  New  Jersey  and  in  1627,  the 
Swedes,  Delaware;  both  colonists  brought  cattle  with  them.  In  1631- 
32-33  Captain  John  Mason  imported  a  large  yellow  breed  of  cattle  from 
Denmark  into  New  Hampshire.  In  New  York  the  cattle  were  largely 
of  Dutch  origin  and  in  Pennsylvania  they  were  brought  in  by  Dutch 
and  Swedish  settlers.  Although  breeds  were  established  at  this  time 
in  Europe  it  is  doubtful  if  many  of  the  cattle  imported  by  the  colonists 
were  purebreds;  most  of  them  were  nondescript  and  from  these  divers 
stocks  originated  the  so-called  " native"  cow  of  America. 

Probably  the  Devon  cattle  that  were  brought  into  New  England  were 
among  the  first  purebred  cattle  to  arrive  in  this  country  as  were  the 
Shorthorns  imported  to  Virginia  by  Miller  in  1783. 

As  a  rule  the  cattle  of  the  United  States  have  come  from  the  British 
Isles,  the  only  important  exceptions  being  the  cattle  of  Holland  and  the 
Brown  Swiss. 

Since  cattle  were  not  native  to  America  there  are  no  strictly  American 
breeds,  but  American  breeders  have  produced  strains  such  as  the  Gore 
breed  and  the  American  Holderness  that  have  attained  considerable 
prominence  but  except  for  the  Polled  Durham  and  the  French-Canadian 
none  has  obtained  a  national  reputation. 

The  Dairy  Type. — Since  there  is  a  direct  relation  between  the  ability 
of  a  cow  to  produce  milk  and  butterfat  profitably,  and  her  conformation 
and  nervous  constitution,  dairymen  seek  animals  of  the  dairy  type.  A 
good  dairy  cow  must  have,  in  addition  to  her  ability  to  assimilate  the 
food  necessary  to  repair  tissue  waste  and  keep  her  organs  in  a  healthy 
functioning  condition,  an  inherited  tendency  to  manufacture  milk  from 
her  provender.  This  predisposition  is  spoken  of  as  dairy  temperament 
and  is  correlated  with  good  health,  a  strong  constitution,  large  feeding 
ability  and  capacious  milk  organs.  Good  health  is  indicated  by  the 
carriage  of  the  animal,  by  mellowness  of  the  hide  and  by  slickness  of  the 
hair. 

A  strong  constitution  is  a  matter  of  inheritance  and  good  care  and 
is  important,  for  a  cow  must  be  strong  and  vigorous  to  make  milk  not 
only  for  10  or  11  months  but  for  years. 

Since  within  the  chest  are  contained  the  vital  organs,  large  chest 


96  CITY  MILK  SUPPLY 

capacity  is  supposed  to  show  strength  of  constitution.  Large  feeding 
capacity  is  essential,  for  whatever  may  be  the  inclination  to  produce,  it 
cannot  be  successful  unless  the  barrel  is  of  sufficient  size  to  handle  large 
amounts  of  the  bulky  foods  The  barrel  should  be  long  between  the 
heart  girth  and  hips,  and  should  be  broad  and  deep,  with  wide  well-sprung 
ribs,  far  apart.  Good  teeth  and  a  broad  muzzle  are  important. 

The  milk  organs  are  the  udder,  teats,  milk  veins,  and  milk  wells. 
The  udder  must  be  large  and  must  have  quality.  It  should  be  broad 
and  long  rather  than  deep  and  the  fore  udder  should  be  well  developed. 
Fat  and  fleshy  udders  are  undesirable,  for  those  distended  with  such  tissue, 
even  though  they  may  be  of  large  size,  may  have  less  capacity  than  smaller 
ones  of  better  quality.  The  teats  should  be  of  convenient  size  and  placed 
at  the  four  corners  of  the  udder.  Since  milk  is  manufactured  from  the 
blood  the  size  and  development  of  the  milk  veins  which  carry  it  from  the 
udder  are  regarded  as  important,  and  large,  crooked,  much-branched 
veins  are  considered  an  indication  of  good  milking  capacity.  However, 
more  importance  may  have  been  attached  to  the  milk  veins  than  is 
warranted.  Dr.  King  of  Maine  pointed  out  that  their  external  appear- 
ance does  not  indicate  their  blood-carrying  capacity  for  the  walls  may 
be  thick  and  the  lumen  small  and  furthermore,  that  in  some  animals  the 
blood  flows  more  rapidly,  than  in  others.  Graves  of  the  Oregon  Experi- 
mental Station  tied  off  the  milk  veins  of  a  cow  so  that  no  blood  could 
pass  through  those  that  are  ordinarily  seen  extending  forward  from  the 
udder  and  found  that  there  were  produced,  neither  ill  effects  on  the  cow 
nor  decrease  in  her  milk  flow.  Careful  investigation  is  needed  to  de- 
termine the  importance  of  these  observations.  The  milk  veins  enter 
the  wall  of  the  belly  through  holes  known  as  milk  wells  and  their  number 
and  size  is  considered  indicative  of  the  amount  of  blood  it  is  possible  to 
carry  back  into  the  body  from  the  udder. 

A  cow  must  have  a  well-developed  nervous  system  to  direct  and  regu- 
late milk  secretion,  digestion  and  other  functions,  but  the  nerves  must  be 
under  control  and  the  disposition  quiet,  for  her  to  rank  well,  as  a  dairy 
animal.  Large  milk  production  seems  to  be  closely  associated  with 
abundant  nervous  force. 

A  proper  nervous  temperament  is  denoted  by  prominent  bright  eyes, 
broad  forehead  and  a  prominent  loose-jointed  backbone.  The  nerves 
branch  off  from  the  spinal  cord  between  the  vertebrae,  hence  the  larger 
the  nerves  the  more  open  the  vertebrae  and  the  wider  apart  the  ribs. 

In  appearance  a  good  dairy  cow  must  show  quality  in  bone,  hair  and 
hide  and  must  have  large  capacity  in  the  rear  where  the  food  is  digested 
and  milk  secreted.  A  good  dairy  cow  does  not  usually  carry  flesh  long 
after  freshening;  therefore  the  hips  and  shoulders  are  angular,  the  back- 
bone prominent  and  the  ribs  plainly  seen. 

Crandall  points  out  that: 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  97 

"Some  breeders  have  selected  on  type  alone  and  thereby  have  produced  animals 
that  to  the  fanciers,  satisfaction  fulfil  the  requirements  of  the  breed  score  cards 
as  to  the  finer  details  of  physical  conformation  but  that  are  not  noted  for  their 
producing  ability.  Other  breeders  relying  less  on  the  breed  score  card  and  on 
show  ring  judgment  have,  while  paying  due  regard  to  physical  fitness  and  the 
breed  characteristics,  made  the  actual  measured  producing  ability  of  the  indi- 
vidual and  of  its  near  ancestors  the  dominating  factor  in  selection  and  so  without 
sacrificing  those  characteristics  of  color  and  milk  quality  which  indicate  purity  of 
blood,  have  improved  the  producing  abilities  of  their  herds.  Thus,  in  the  higher 
producers  of  the  four  principal  dairy  breeds,  has  been  developed  a  similarity  of 
type,  characterized  by  good  dairy  temperament  or  ability  to  produce  milk,  large 
feeding  capacity,  strong  constitution  and  capacious  milking  organs.  That  con- 
tinual selection  and  development  for  production  has  evolved  a  type  common  to 
all  breeds  is  convincing  evidence  that  such  a  type  is  best  adapted  for  high  produc- 
tion. It  follows,  that  when  it  is  desired  to  distinguish  profitable  from  unprofitable 
cows  judgment  may  be  based  upon  a  simple  standard  or  score  card  considering 
physical  requirements  which  are  logically  and  physiologically  related  to  the 
organic  functions  necessary  to  milk  production.  These  functions  are  those  of 
the  vital  organs  to  furnish  pure  blood  to  the  body  and  secretory  glands,  of  the 
digestive  organs  to  digest  large  amounts  of  food  and  to  make  available  material 
for  use  in  the  body  processes  and  in  milk  secretion,  of  the  milking  organs  to  secrete 
large  quantities  of  milk  from  the  blood  coming  to  them,  of  the  generative  organs 
to  produce  strong  offspring  and  of  the  nervous  system  to  stimulate  and  to  co- 
ordinate the  activities  of  all  organs  and  glands  in  the  efficient  production  of  milk. 
A  weakness  in  any  one  of  these  functions  weakens  the  production  of  the  animal. 
That  a  judge  must  weigh  the  varying  degrees  of  excellence  in  the  combinations 
of  these  functions  occurring  in  different  animals,  explains  the  impossibility  of 
his  accurately  estimating,  producing  ability. 

"  There  are  qualities  of  form,  capacity  and  material  in  certain  body  parts  and 
their  combination  which  indicates  their  adaption  and  capacity  for  milk  produc- 
tion. A  standard  which  considers  these  combinations  of  parts  directly  in  their 
relation  to  function  emphasizes  that  function  and  considers  the  physical  parts 
only  as  a  means  in  estimating  the  ability  of  that  function  to  perform.  The  user 
of  such  a  standard  thinks  and  judges  in  terms  of  function,  and  not  of  parts. 

"The  following  score  card  in  use  at  the  University  of  Illinois  is  made  up  with 
the  above  requirements  in  mind.  After  practice  in  its  use,  few  students  fail  to 
distinguish  the  better  of  two  cows  when  the  difference  in  their  yearly  production 
is  4,000  Ib.  of  milk  or  more  and  many  students  succeed  in  selecting  the  better 
animal  when  the  difference  between  the  two  is  only  2,000  in  a  yearly  production 
of  10,000  Ib.  or  more." 

The  cow  of  modern  herds  is  not  only  a  splendid  example  of  man's 
conquest  of  nature  by  domestication  of  wild  animals  but  is  a  triumph 
of  the  breeder's  art.  The  animals  have  been  plastic  in  his  hands  and 
have  been  moulded  to  man's  needs  until  they  have  been  developed  to 
such  a  degree  that  they  may  be  regarded  as  highly  perfected  machines  for 
efficiently  producing  food.  Breeders  have  developed  three  types  of 
animals,  beef  cattle,  especially  adapted  for  meat  production,  dairy  cattle, 


CITY  MILK  SUPPLY 


specialized  for  milk  production  and  general  or  dual-purpose  cattle,  which 
are  supposed  to  be  fitted  to  the  needs  of  the  general  farmer  and  are 
claimed  to  be  good  for  both  .milk  and  beef  production. 

University  of  Illinois — Dairy  Cow  Score  Card 
Scale  of  Points— Cow 


Indicating 

dairy 
tendency 

or 

temperament 
30 


Indicating 

constitution 

and  general 

health 

16 

Indicating 

feeding 

capacity 

24 


Indicating 

development 

of  maternal 

function 

30 


WEIGHT — Estimated — pounds ;  actual — pounds 

FORM — Parts  well  balanced ;  tendency  to  triple  wedge  shape  as 

viewed  from  front,  top,  and  side 

Shoulders,  withers,  hip,  and  pin  bones  angular  and  free 
from  fleshiness,  (period  of  lactation  to  be  con- 
sidered) 

Thighs  incurving,  thin,  wide  apart 
Open  conformation  in  withers,  shoulders,  and  back- 
bone 
QUALITY — Bone,  medium  as  indicated  by  clean  face  and  legs 

and  long,  slim  tail 
Hide  free  from  fleshiness 
NERVOUS  DEVELOPMENT — Face  broad  between  eyes,  dished; 

eye  prominent,  clear,  quiet 
Backbone  large  and  prominent 
Disposition  active,  with  good  nerve  control 
BREED  CHARACTER — Size  and  color,  indicating  a  high  percent- 
age of  the  blood  of  some  one  dairy  breed 

CHEST — X)eep  and  full,  showing  lung  capacity;  wide  on  floor 
and  full  at  elbows 

CONDITION — Thrifty  and  vigorous;  skin  mellow,  loose,  not 
papery  or  hard;  hair  fine  and  soft,  not  wiry 

BARREL — Long;  ribs  broad,  wide  apart,  loin  long 
Wide;  ribs  well  sprung,  loin  broad 
Deep ;  ribs  long 
i  MUZZLE — Wide,  full  lips;  strong  jaws,  good  teeth 

UDDER — Capacity;  large  in  size  and  of  good  quality 

Shape;  attached  high  and  wide  at  back;  extending  well 

forward ;  quarters  evenly  developed 
TEATS — Uniform;  of  convenient  size  and  length;  free  from 

lumps  and  warts,  extra  orifices  and  leakage 
MILK  VEINS — Large,    tortuous,    and    much   branched;    milk 

wells  large 
RUMP — Broad  at  both  hips  and  pin  bones;  level;  indicative  of 

pelvic  capacity 

TOTAL 


Pos- 
sible 
score 


12 
6 
4 
4 
4 
100 


DAIRY  CATTLE  AND  THE  DAIRY-FARM 


99 


In  the  United  States  the  strictly  dairy  breeds  of  cattle,  among  which 
the  most  prominent  are  the  Holstein,  Ayrshire,  Brown  Swiss,  Guernsey 
and  Jersey,  are  the  dominant  animals  and  are  forcing  their  way  into  all 
districts  that  are  important  sources  of  city  milk  supply.  They  are  the 
answer  of  those  breeders  who  have  given  milk  production  special  thought 
to  the  question  of  milk  supply,  for  their  inherited  tendency  to  make 
milk  adapts  them  to  cope  with  the  problem. 

Holstein-Friesian. — The  Holstein-Friesian  is  one  of  the  largest 
breeds  of  cattle.  A  reasonable  and  moderate  weight  for  an  aged  bull  is 
from  1,900  to  2,000  Ib.  and  for  cows  is  from  1,250  to  1,400  Ib.  The  calves 
at  birth  average  90  Ib.  in  weight.  In  America  the  animals  are  almost 
always  black  and  white  displayed  in  patches;  in  the  Netherlands  several 
purebred  herds  of  red  and  white  animals  exist.  There  is  some  evidence  to 
show  that  red  was  the  original  color  and  that  the  black  was  acquired  from 
Jutland  cattle  in  the  latter  part  of  the  18th  century.  In  shape  the 
animals  have  a  long  head,  dark  or  flesh-colored  muzzle,  and  large  long 
bodies,  with  well-sprung  ribs  denoting  great  feeding  capacity.  The  hips 
are  often  prominent  and  the  rump  long  and  level.  The  udder  is  large 
and  U-shaped  with  big  teats  placed  at  the  corners.  The  cows  are 
copious  milk  producers;  fair  specimens  should  yield  from  7,000  to  9,000 
Ib.  of  milk  a  year  and  many  records  far  surpass  this.  The  milk  is  chalky 
white  and  averages  about  3.5  per  cent,  butterfat  but  varies  within 
wide  limits,  some  animals  producing  milk  of  lower  test  than  the  legal 
standard  required  by  many  of  the  States  while  others  test  above  the 
average.  As  a  butterfat  producer  the  breed  takes  high  rank  because 
of  the  big  milk  yield.  The  fat  globules  are  small  and  do  not  rise  as  rapidly 
nor  separate  by  gravity  as  perfectly  from  the  milk  serum  as  do  the 
globules  of  the  Jersey  and  Guernsey  breeds;  consequently  the  cream  line 
is  not  so  well  defined. 

TABLE  31. — HOLSTEIN — FRIESIAN  RECORDS 


Cow 

Pounds  of 
milk 

Pounds  of 
butterfat 

Average  per  cent, 
of  butterfat 

Tilly  Alcarta  

30,452 

951 

3  13 

Creamelle  Vale  

29,591 

925 

3.12 

Finderne  Pride  Johanna  Rue 

28,404 

1,176 

4  14 

Dutchess  Skylark  Ormsby  
Cioantha  4th's  Johanna 

27,761 
27,432 

1,205 

998 

4.34 
3  63 

Banostine  Belle  De  Kol  

27,404 

1,058 

3.86 

Highlawn  Hartog  De  Kol       .    . 

25,592 

998 

3  90 

Pontiac  Clothilde  De  Kol  

25,318 

1,017 

4.01 

Finderne  Holingen  Fayne 

24612 

1  116 

4  53 

Lindenwood  Hope 

20  405 

953 

4  56 

At  the  present  time  the  breed  is  generally  distributed  over  the  United 


100 


CITY  MILK  SUPPLY 


Courtesy  of  W.  J.  Fraser. 

FIG.  la. — Holstein-Friesian  bull,  Sarcastic  Lad. 


Courtesy  of  W.  J.  Fraser, 

FIG.  2. — Holstein-Friesian  cow,  Tina  Clay  Pieterje  Bell. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  .  101 


States  and  is  a  favorite  in  sections  where  production  of  milk  for  city 
consumption  is  the  chief  industry  because  the  cows  give  large  quantities 
of  good  milk  of  low  fat  content  that  can  be  sold  cheap  at  a  profit.  The 
Holstein-Friesians  are  good  cows  for  patrons  selling  to  creameries  and 
cheese  factories  that  purchase  milk  by  bulk  and  not  on  the  butterfat 
basis.  Partizans  of  the  breed  claim  that  because  of  the  low  fat  content 
of  the  milk  and  the  small  size  of  the  fat  globules  the  milk  is  especially 
adapted  to  infant  feeding. 

Admirers  of  other  breeds  contend  that  when  the  milks  thereof  are 
properly  diluted  they  give  results  in  infant  feeding  that  are  as  satisfactory 
as  those  obtained  with  Holstein  milk. 

Ayrshire. — The  Ayrshire  originated  in  the  county  of  Ayr  in  southern 
Scotland.  The  basal  stock  was  the  native  cattle  of  the  region  but  the 
breed  seems  to  have  been  evolved  by  the  crossing  of  many  of  the  best 
milk-producing  breeds.  Several  authorities  instance  the  use  of  different 
cattle  by  various  breeders  in  improving  the  breed.  The  Shorthorn, 
Dutch,  Devon,  Channel  Island,  West  Highland  and  Hereford  cattle 
all  are  mentioned  as  having  been  utilized  in  developing  the  Ayrshire. 
The  original  marking  appears  to  have  been  black,  but  about  1780  red  and 
white  became  fashionable,  later  brown  and  white  mottled  cattle  were 
preferred  and  of  recent  years  there  has  been  a  craze  for  white  animals 
with  a  minimum  of  red  or  brown.  Ayrshire  bulls  weigh  from  1,400  to 
2,000  and  the  cows  average  1,000  Ib.  The  bodies  of  the  animals  are 
capacious,  the  ribs  long  and  well-sprung  while  the  rump  is  usually  high, 
broad  and  long.  The  uniform  well-shaped  udders  are  notable.  They 
are  not  pendant  but  the  forepart  has  unusual  extension  and  the  rear  is 
carried  w^ell  up  behind.  The  teats  are  well-placed  but  are  apt  to  be 
inconveniently  small  for  milking.  American  breeders  are  endeavoring 
to  overcome  this  defect. 

Ayrshires  were  first  brought  to  Canada  between  1820  and  1830. 
The  first  animals  to  come  into  the  United  States  are  said  to  be  some  that 
were  imported  to  Connecticut  in  1822  but  this  is  not  certain,  and  many 
regard  the  Massachusetts  importation  of  1837  as  the  first.  For  a  time 
thereafter  importation  continued  but  it  dropped  off  only  to  be  resumed 
actively  in  recent  years. 

The  Ayrshire  has  always  been  known  as  a  good  milk  producer;  cows 
rated  as  fair  specimens  of  the  breed  will  give  7,500  Ib.  of  milk  a  year. 
The  milk  is  white  and  tests  on  the  average  of  3.8  per  cent,  butterfat.  The 
fat  globules  are  small  and  the  total  solids  high.  The  milk  has  been  called 
the  perfect  milk  by  admirers  of  the  breed,  partly  because  of  the  propor- 
tion of  fat  to  solids-not-fat,  and  is  especially  recommended  by  many  for 
infant  feeding.  For  city  milk  supply  the  breed  is  satisfactory  as  the 
cows  are  consistent  producers  of  milk  that  tests  12.5  per  cent,  total  solids 
and  a  trifle  under  4  per  cent,  butterfat.  As  butter  cows,  the  Ayrshires 


102 


CITY  MILK  SUPPLY 


Courtesy  of  D.  Whiting  &  Sons. 

FIG.  3. — Ayrshire  bull,  King  of  Arludo. 


Courtesy  of  the  Ayshire' Breeders  Association. 

FIG.  4. — Ayrshire  cow,  Garclaugh  May  Mischief. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM 


103 


have  not  been  so  successful  as  some  other  breeds.  In  Scotland,  large 
quantities  of  cheddar  cheese  are  made  from  the  milk  and  for  cheese  mak- 
ing the  milk  is  of  the  best  because  of  its  small  fat  globules  and  high  protein 
content. 

TABLE  32. — AYRSHIRE  RECORDS 


Cow 

Pounds  of 
milk 

Pounds  of 
butterfat 

Average  per  cent, 
of  butterfat 

Garclaugh  May  Mischief  

25  328 

895 

Q     KQ 

Auchenbrain  Brown  Kate  4th 

23,022 

917 

Q  qq 

Lilly  of  Willowmoor  

22  596 

955 

4  91 

Garclaugh  Spottie  

22  589 

ei  A 

3fi1 

Auchenbrain  Yellow  Kate  3d  

21  123 

888 

4  91 

Gerrantown  Dora  

21  023 

804 

300 

Jean  Armour  

20  174 

774 

304. 

Rena  Ross  2d  

18  849 

713 

Q  70 

Nethehall  Brownie  9th  

18  110 

820 

4.  cq 

Henderson's  Dairy  Queen  

17  974 

738 

4   10 

Agnes  Wallace  of  Maple  Grove  

17,657 

821 

4.65 

Brown  Swiss. — The  Brown  Swiss  cattle  were  introduced  to  the  United 
States  from  Switzerland  which  country  is  famed  for  this  breed  and  also 
for  the  Simmenthal. 

The  Brown  Swiss  were  first  brought  to  the  United  States  in -1869 
when  they  were  imported  to  Massachusetts  from  the  Canton  of  Schwyz. 
Other  importations  followed  till  at  the  present  time  they  are  found  in 
almost  every  State  but  not  in  large  numbers.  The  semiofficial  records 
of  18  cows  in  the  herd  of  E.  M.  Barton  of  Hinsdale,  111.,  gives  an  average 
of  9,448.8  Ib.  of  milk  and  363.7  Ib.  of  butterfat  per  cow  per  year,  making 
the  average  butterfat  test  3.84  per  cent.  Of  these  cows  seven  produced 
over  10,000  Ib.  of  milk  a  year  apiece,  the  maximum  being  11,274  Ib.  con- 
taining 391  Ib.  of  butterfat.  The  maximum  butterfat  yield  per  cow  was 

TABLE  33. — BROWN  Swiss  RECORDS 


Cow 

Pounds  of 
milk 

Pounds  of 
butterfat 

Average  per  cent, 
of   butterfat 

College  Bravura  2d  

19  460 

7QC 

4  in 

Ethel  B  

18  816 

780 

41  A 

Lottie  G.  B. 

1  7  cqc 

Afi/f 

lola  
Rosalind  B  

16,844 
16  804 

DO4 

685 

797 

3.71 
4.07 

Kaliste  W  

ift  AOQ 

(*  Pf) 

.66 

OlaB. 
My  Own  Baby  

15,602 
15  769 

DOU 

548 

A9Q 

.94 
3.51 

3-1    A 

Merry  Merney  

15  679 

«00 

.  14 

4  no 

Malitia  May  

14  791 

(\14. 

4OQ 

104 


CITY  MILK  SUPPLY 


Courtesy  of  E.  M.  Barton. 


FIG.  5. — Brown  Swiss  bull,  Junker. 


Courtesy  of  E.  M.  Barton. 


FIG.  6. — Brown  Swiss  cow,  Hirz. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  105 

455  Ib.  from  10,959  Ib.  of  milk,  making  the  average  butterfat  test  for  the 
period  4.15  per  cent.  In  Switzerland  the  breed  is  frankly  a  dual  purpose 
one  but  the  breeders  of  the  United  States  announce  that  the  animals  are 
to  be  developed  here  as  a  dairy  breed.  The  color  of  the  milk  is  about  the 
same  as  that  of  the  Shorthorn  and  seems  well-suited  for  city  milk  supply. 
Some  Brown  Swiss  records  are  given  in  Table  33. 

The  Channel  Islands  Cattle. — The  Guernsey  and  Jersey  cattle 
originated  in  the  Channel  Islands,  a  group  that  is  partly  made  up  of  the 
islands  of  Alderney,  Guernsey,  Sark  and  Jersey  and  that  is  located  in 
the  English  Channel  directly  south  of  England,  from  4  to  40  miles  off  the 
coast  of  France.  The  origin  of  the  breeds  is  somewhat  obscure  but  they 
are  supposed  to  have  been  derived  from  a  cross  of  the  cattle  of  Brittany 
and  Normandy  with  cattle  native  to  the  islands.  Formerly  both  in 
England  and  the  United  States  the  cattle  of  the  Channel  Islands  were 
called  Alderneys,  a  term  that  included  both  Guernseys  and  Jerseys. 
To  protect  their  stock  from  cattle  diseases  and  to  maintain  its  purity 
the  inhabitants  of  the  Island  of  Jersey  as  early  as  1763  passed  laws 
prohibiting  the  importation  of  cattle  from  France;  in  1789  the  prohibition 
was  extended  to  all  cattle  and  there  has  been  no  importation  since.  A 
few  years  later  the  Island  of  Guernsey  adopted  the  the  same  policy. 

Guernsey. — The  Guernsey  is  bred  on  the  islands  of  Guernsey  and 
Alderney  where  the  intent  is  to  secure  uniformity  of  type  and  good  pro- 
ducing animals.  A  mature  bull  should  weigh  about  1,500  Ib.  and  a  cow 
about  1,050.  The  animals  are  larger  and  of  a  less  refined  type  than  the 
Jerseys,  are  yellowish,  brownish  or  reddish  fawn,  frequently  with  white 
markings  on  the  legs  and  under  part  of  the  body.  The  muzzle  is  buff  or 
flesh-colored  and  is  surrounded  by  a  whitish  or  yellowish  circle  of  hair. 
The  skin  is  mellow,  thin,  elastic  and  yellow,  the  horns  and  hoofs  are 
amber-colored,  and  in  the  cows,  the  horns  often  curve  gracefully  over  the 
face.  The  udder  is  large  and  the  teats  are  of  a  good  size. 

The  breed  was  apparently  first  introduced  into  this  country  from 
Alderney  to  Philadelphia  in  1818.  Importations  from  Guernsey  came 
later  and  from  1830  to  1870  the  animals  were  brought  to  Pennsylvania, 
Massachusetts,  and  other  points  along  the  Atlantic  coast. 

The  cows  rank  high  as  milk  producers,  a  yield  of  5,000  Ib.  a  year  is 
easily  averaged  by  a  herd,  and  herds  are  reported  averaging  double  this 
amount.  The  milk  is  very  popular  with  consumers,  because  of  its 
rich  yellow  color.  The  fat  globules  are  large  so  that  the  milk  creams 
easily  and  gives  a  sharply  defined  cream  line. 

As  butter  producers  the  cows  have  won  special  distinction.  Owing 
to  the  natural  yellow  color  of  the  fat  globules,  the  butter  has  a  beautiful 
golden  hue  that  makes  the  addition  of  butter  color  superfluous.  Some 
yearly  records  of  milk  and  butterfat  production  are  given  in  Table  34. 


106 


CITY  MILK  SUPPLY 


Courtesy  of  the  American  Guernsey  Cattle  Club. 

FIG.  7. — Guernsey  bull,  Imp.  Moss  Raider. 


Courtesy  of  the  American  Guernsey  Cattle  Club. 

FIG.  8. — Guernsey  cow,  Murne  Cowan. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM 

TABLE  34. — GUERNSEY  RECORDS 


107 


Cow 

Pounds  of 
milk 

Pounds  of 
butterfat 

Average  per  cent, 
of  butterfat 

Murne  Cowan 

24,008 

1,098 

4  54 

May  Rilma  

19,639 

1,059 

5.39 

Spotswood  Daisy  Pearl 

18,602 

957 

5.14 

Dolly  Dimple  
Imp   Daisy  Moon  3d 

18,459 
18,019 

907 

928 

4.91 
5.15 

Julie  of  the  Chene  

17,661 

953 

5.39 

Dairy  Maid  of  Pinehurst 

17,285 

911 

5  27 

Miranda  of  Mapleton  
Yeksa  Sunbeam  

16,630 
14,921 

927 
857 

5.51 
5.74 

Imp.  Beauty  of  Park  Farm 

14,686 

899 

6.12 

Jersey. — The  Island  of  Jersey  supports  about  13,000  cattle. 
The  Jerseys  like  the  Guernseys  are  believed  to  be  descended  from  the 
French  cattle  of  Normandy  and  Brittany.  It  is  probable  that  the  cattle 
of  the  Channel  Islands  were  at  one  time  essentially  alike  and  as  the  two 
breeds  have  been  developed  under  practically  identical  climatic  conditions 
the  differentiation  of  the  cattle  is  the  result  of  the  different  ideals  of  the 
breeders  in  Guernsey  and  Jersey.  While  the  Guernsey  breeders  were 
striving  for  uniformity  of  type  and  improved  production,  the  Jersey 
breeders  aimed  at  evolving  an  animal  of  refined  type  and  perfect  form. 
Both  have  been  successful  in  developing  breeds  famed  for  high  and  eco- 
nomical fat  production.  In  America,  Jerseys  have  been  very  popular  but 
American  breeders  have  paid  less  attention  to  form  and  more  to  produc- 
tion than  those  of  Jersey;  consequently  there  are  in  America  two  types 
of  animals,  the  small  shapely  ones,  imported  from  the  Island  and  the 
coarser  plainer  type  produced  here.  In  the  show  ring  the  standard  of 
judging  has  been  such  as  to  establish  the  success  of  the  imported  animals 
while  the  records  for  production  of  the  cattle  of  the  American  breeders 
has  surpassed  those  of  the  Island  type  both  in  their  native  land  and  here. 
The  future  success  of  the  breed  in  the  United  States  as  a  practical  dairy 
animal  seems  to  depend  on  the  wise  development  of  the  American  type. 
As  a  persistent  milk  producer  and  as  a  family  cow,  the  Jersey  is  unexcelled. 

The  animals  are  lean  and  graceful  with  the  wedge  shape  markedly 
developed.  They  give  the  impression  of  having  much  capacity  and 
power  in  a  small  body.  In  proportion  to  the  size,  the  barrel  is  large  and 
the  ribs  well-sprung.  The  udders  are  mellow,  and  milk  out  well,  but  not 
a  few  of  the  cows  show  a  weak  fore  udder,  though  this  is  by  means  gener- 
ally true,  for  others  leave  nothing  to  be  desired  in  this  respect.  The 
head  is  rather  short  and  broad  between  the  eyes  which  are  prominent; 
the  face  is  slightly  dished.  The  color  of  the  animals  runs  from  gray 
through  fawn  to  a  dark  brown.  Some  excellent  animals  are  brindled 


108 


CITY  MILK  SUPPLY 


PHH^  ^B^V^ 


Courtesy  of  Hood's  Farm. 

FIG.  9.— Jersey  bull,  Pogis  99th  of  Hood's  Farm. 


Courtesy  of  Hood's  Farm. 

FIG.  10. — Jersey  cow,  Lass  66th  of  Hood's  Farm. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM 


109 


but  they  are  looked  upon  with  disfavor  by  those  who  place  the  tint  of  a 
cow  above  her  performance  at  the  pail.  The  Jerseys  are  graceful,  active 
animals  of  nervous  temperament  which  predicates  intelligent  handling, 
to  get  the  best  out  of  them.  The  breed  is  prepotent  and  the  animals 
mature  early. 

The  first  definite  importation  of  cattle  to  the  United  States  from  the 
Island  of  Jersey  seems  to  have  been  that  to  Hartford,  Conn.,  in  1850. 
After  that,  importations  to  Connecticut,  Massachusetts,  Maryland,  New 
York,  Pennsylvania  and  Canada  became  frequent.  In  importing  from 
the  Island,  the  blood  of  certain  famous  bulls  has  been  most  sought.  This 
has  resulted  in  the  recognition  of  families  of  Jerseys  in  this  country.  The 
most  famous  is  the  St.  Lambert  which  Eckles  states  originated  in  Canada 
and  is  descended  from  cattle  imported  by  Stevens  of  Montreal  and  St. 
Clair  of  Vermont.  The  bulls  Stoke  Pogis  and  Stoke  Pogis  3d  are  sup- 
posed to  be  predominant  factors  in  the  formation  of  the  family. 

As  a  rule  Jerseys  are  not  large  milk  producers  but  it  is  not  unusual  for 
cows  to  give  6,000  Ib.  of  milk  a  year.  The  fat  globules  are  large  and 
yellow  so  that  milk  creams  and  churns  easily  and  gives  a  sharply  defined 
cream  line.  Being  very  rich  it  is  very  popular  with  those  who  can  afford 
it.  As  butter  producers  Jerseys  rank  high.  Some  Jersey  records  are 
given  in  Table  35. 

• 

TABLE  35. — JERSEY  RECORDS 


Cow 

Pounds  of 
milk 

Pounds  of 
butterfat 

Average  per  cent, 
of  butterfat 

Eminent's  Bess  

18,782 

962 

5.12 

Lass  40th.  of  Hood's  farm 

18661 

854 

4  52 

Lass  66th  of  Hood's  farm.   

17,794 

911 

5  11 

Sophie  19th  of  Hood's  farm  

17,557 

999 

5.69 

Jacoba  Irene     .  .         .    . 

17,253 

953 

5  52 

Temisia's  Owl's  Rose  

17,055 

863 

5.06 

Spermfield  Owl's  Eva 

16,457 

993 

6  03 

Olga  4th's  Pride  

16,275 

851 

5.22 

Olympiads  Fern 

16,148 

938 

5  81 

Merrv  Maiden  .  . 

6.896 

560 

8.13 

Other  breeds  of  minor  importance  in  the  United  States  are  the  French 
Canadian,  Dutch  Belted  and  Kerry. 

French-Canadian. — The  French-Canadian  cattle  are  interesting  be- 
cause they  form  the  only  successful  distinctly  dairy  breed  that  has 
been  developed  in  America.  Grisdale  says  of  them,  that  they  are  sup- 
posed to  be  derived  from  cattle  imported  from  Normandy  or  Brittany 
by  the  French  settlers  of  the  17th  century;  that  many  years  of  roughing 
it  along  with  the  people  has  made  them  hardy  and  that  the  process  of 


110 


CITY  MILK  SUPPLY 


Courtesy  of  Dr.  J.  A.  Couture. 

FIG.  11. — French-Canadian  bull,  Fortune  d' Or. 


Courtesy  of  Dr._J.  A.  Couture. 

FIG.  12. — French-Canadian  cow,  Filie. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  111 

.selection  which  has  evolved  them  has  made  them  productive  on  light, 
poor  rations.  He  says  further  that  the  French-Canadian  cows  are  worthy 
of  much  consideration  where  a  hardy  breed  of  rustlers  is  required.  The 
individual  cow  is  somewhat  small,  weighing  only  700  to  900  Ib.  A  bull 
weighs  about  1,000  Ib.  In  general  conformation  they  are  somewhat 
rough  and  angular;  in  the  cows  the  wedge  shape  is  present.  The  color 
is  black  or  dark  brown.  As  milk  producers  they  resemble  the  Jersey 
though  in  quantity  and  quality  they  fall  somewhat  behind  that  breed. 
An  average  of  6,500  Ib.  of  milk  of  a  little  over  4  per  cent,  butterfat  is 
about  standard.  The  herd  book  dates  from  1886  and  is  kept  by  the 
French  Canadian  Cattle  Breeders  Association. 

Dual-purpose  Cattle. — The  dual-purpose  cattle  have  been  under 
sharp  discussion  for  a  long  time.  Their  advocates  claim  that  they  com- 
bine the  desirable  features  of  both  the  beef  and  dairy  types,  the  animals 
being  economical  milk  producers  and  also  valuable  meat  animals.  The 
opponents  of  the  type  vigorously  assert  that  there  is  no  such  thing  as  a 
dual-purpose  animal,  that  the  creatures  either  run  toward  beef  production 
or  toward  milk  production  and  in  either  case  are  only  mediocre  per- 
formers. At  the  present  time  the  tendency  among  the  shrewdest  farmers 
is  probably  to  rear  either  herds  of  beef  or  of  dairy  cattle;  at  the  same 
time  it  is  recognized  that  the  dual-purpose  animals  are  invaluable  to  a 
region  that  is  passing  from  beef  production  into  dairying.  Herdsmen 
who  have  been  used  to  the  rough-and-ready  ways  of  cattlemen  find  diffi- 
culty in  turning  to  the  care  of  heavy  milk-producing  cows  for  they  need 
more  careful  and  individual  attention. 

Shorthorn. — The  Shorthorn  is  the  dual-purpose  animal  that  is  of 
greatest  importance  in  milk  production.  This  breed  originated  in  north- 
eastern England  in  the  counties  of  York,  Durham  and  Northumberland 
and  has  spread  over  Great  Britain  and  thence  over  the  civilized  world. 
Cattle  of  this  type  are  believed  to  have  existed  previous  to  1600.  The 
first  Shorthorns  were  imported  to  America  in  Virginia  in  1783.  The 
breed  is  one  of  the  most  popular  in  the  United  States.  As  a  dairy  animal 
the  Shorthorn  has  had  a  larger  influence  in  England,  where  it  is  a  chief 
dairy  cow,  than  anywhere  else  and  much  of  the  milk  shipped  to  London 
comes  from  Shorthorn  herds.  In  the  United  States,  particularly  in  the 
central  West,  a  considerable  part  of  the  milk  supply  is  furnished  by  these 
animals.  There  are  really  two  classes  of  Shorthorns;  those  that  are 
unquestionably  of  the  beef  type  and  those  of  "milking  strain"  thai  make 
satisfactory  dairy  cows.  Eckles  says  that  in  the  United  States  Shorthorns 
have  been  developed  almost  exclusively  for  beef  production  and  that 
consequently  the  typical  purebred  animal  of  this  country  has  no  claim 
to  be  regarded  as  a  dairy  animal  but  that  there  is  a  revival  of  interest  in 
the  milk-producing  strain  which  of  late  has  led  to  importation  of  animals 
of  the  dairy  type. 


112 


CITY  MILK  SUPPLY 


Some  American  Shorthorn  records  which  for  the  most  part  are  those 
given  by  Eckles  appear  in  Table  36. 

TABLE  36. — AMERICAN  SHORTHORN  RECORDS  (ECKLES) 


Cow 

Pounds  of 
milk 

Pounds  of 
butterfat 

Per  cent,  of 
butterfat 

Rose  of  Glenside  

18,075 

625 

3.46 

Mamie's  Murriel 

16,201 

575 

3  49 

Lula 

12341 

515 

4  17 

Panama  Lady      

13,789 

490 

3.55 

Florence 

10  438 

424 

4  06 

College  Moore  .  . 

9,896    . 

407 

4.11 

The  animals  are  commonly  red,  white  or  roan;  cows  of  the  dairy 
type  weigh  1,200  to  1,350  Ib.  and  at  birth  their  calves  weigh  70  to  90  Ib. 
Their  milk  on  test  gives  3.6  to  4  per  cent,  butterfat  and  about  12.5  per 
cent,  total  solids. 

Choice  of  Breed. — With  these  breeds  to  choose  from  the  question 
naturally  arises  which  is  best,  and  to  this  query  no  definite  answer  can 
be  given  for  the  reason  that  each  has  its  proper  place  and  use  and  under 
intelligent  encouragement  will  yield  good  results.  As  a  rule  the  predilec- 
tion of  a  dairyman  for  some  one  of  the  breeds  is  often  a  determining  factor 
in  choice,  and  rightly  so,  for  a  man  is  likely  to  succeed  best  with  animals 
for  which  he  has  a  peculiar  interest  and  fondness.  Broadly  speaking  it 
is  generally  wise  to  build  the  herd  of  animals  that  are  common  to  the 
region  in  which  the  farm  is  situated,  because  the  dairyman  gains  from 
the  mutual  interest  of  local  breeders,  the  presence  of  fine  specimens  of 
the  breed  and  the  renown  of  the  district  as  the  home  of  many  good  cattle 
of  a  particular  sort.  Thus  buyers  from  abroad  seek  out  the  place  so  that 
there  is  likely  to  be  a  ready  market  at  good  prices  for  surplus  stock. 
Economic  conditions  have  to  be  carefully  considered;  if  the  region  is 
one  where  the  cost  of  labor,  or  feed  or  the  high  price  of  land  or  high  taxes 
put  it  at  a  disadvantage  in  competing  with  others  in  any  branch  of  pro- 
duction this  fact  should  be  recognized  and  choice  be  made  accordingly. 
If  it  is  intended  to  sell  milk  to  creameries  or  cheese  factories  that  buy  in 
bulk  instead  of  on  a  butterfat  basis  or  if  milk  is  to  be  put  out  to  a  city 
milk  trade  that  seeks  only  low  price,  the  breeds  that  produce  large  quanti- 
ties of  milk  will  naturally  be  selected.  On  the  other  hand,  if  pay- 
ment for  milk  is  made  on  a  butterfat  basis  or  if  it  is  intended  to  capture 
a  city  milk  trade  that  will  pay  well  for  rich  milk  the  breeds  yielding  milk 
testing  high  in  butterfat  will  be  picked  out.  Economy  of  milk  production 
by  the  animals  has  to  be  taken  into  account.  Cows  that  will  produce  the 
most  milk  or  those  making  the  most  butterfat  with  the  least  consumption 
or  cost  of  feed  are  sought. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  113 

It  is  best  to  have  the  herd  composed  of  a  single  breed  of  cattle,  but 
where  heavy  producing  animals  are  used  to  supply  milk  to  the  public 
some  keep  a  few  cows  of  the  breeds  that  test  high  in  butterfat  in  order 
to  hold  the  herd  milk  well  above  the  legal  requirements  and  to  impart 
color  to  the  milk  as  well  as  to  help  secure  a  sharp  cream  line. 

Importance  of  a  Purebred  Bull. — Few  farmers  can  afford  purebred 
herds  which  would  be  serious  were  it  not  possible,  by  the  use  of  a  purebred 
bull,  and  by  raising  his  heifer  calves  to  breed  up  a  grade  herd  that  will 
compare  favorably  with  and  perhaps  even  surpass  the  production  of  a 
purebred  herd.  Progressive  dairymen  fully  appreciate  this  and  in  many 
places  maintain  bull  associations  which  enable  the  farmer  of  moderate 
means  to  secure  service  of  the  best  animals.  Normally  a  scrub  bull 
depresses  the  milk  and  butterfat  production  of  a  herd  and  a  purebred 
bull  raises  it  but  sometimes  a  purebred  animal  is  a  failure.  The  fitness 
of  a  bull  to  head  a  herd  is  judged  by  his  conformation  and  the  records 
of  his  female  progenitors  in  milk  and  butterfat  production.  The  test  of 
his  fitness  is  his  ability  to  maintain  the  vigor  of  the  herd  and  beget 
daughters  with  better  records  of  milk  and  butterfat  production  than  their 
dams. 

Importance  of  Testing  Cows. — A  good  judge  of  cattle,  guided  by  his 
expert  knowledge  of  type  and  form  can  pick  out  animals  so  shrewdly 
that  the  herd  will  contain  but  few  poor  ones.  However,  there  are  always 
those  that  do  not  work  out  according  to  form  and  the  difference  between 
the  best  performers  and  the  worst  is  considerable.  Indeed,  between 
cows  of  the  same  breed  there  is  likely  to  be  as  much  variation  as  regards 
quantity  and  quality  of  milk  production  as  there  is  between  cows  of 
different  breeds.  Moreover  many  dairymen  lack  the  knowledge  to 
enable  them  to  select  good  milk-producing  cows  for  their  herds. 
Precise  knowledge  of  the  actual  value  of  a  cow  as  a  producer  of  milk 
and  butterfat  can  be  obtained  only  by  the  use  of  scales  and  the  Babcock 
butterfat  tester.  The  milk  of  each  cow  should  be  weighed  at  every 
milking  both  because  it  gives  the  basis  for  rational  feeding  and  because 
it  measures  the  cows  capability  as  a  milk  producer.  The  milk  of  each 
cow  may  be  sampled  at  every  milking  and  used  to  form  a  composite 
sample  that  is  kept  sweet  by  an  added  preservative  and  tested  for  butter- 
fat  at  the  end  of  a  week,  or  samples  may  be  taken  and  tested  less 
frequently.  From  these  tests  and  the  amount  of  milk  given  by  the 
cow  her  total  butterfat  production  can  be  computed.  So,  it  is  possible 
to  determine  whether  the  cow  is  a  profit  maker  or  a  star  boarder.  The 
importance  of  thus  keeping  tally  on  the  cow's  performance  has  been  shown 
over  and  over  again  both  abroad  and  in  this  country.  Figures  illustrative 
of  what  may  be  learned  from  such  records  are  given  by  W.  J.  Fraser. 

The  dairy  department  of  the  University  of  Illinois  bought  the  best 
and  poorest  cows  from  six  different  herds,  brought  them  to  the  Uni- 


114 


CITY  MILK  SUPPLY 


versity  and  kept  account  of  all  the  feed  they  consumed  and  of  the  milk 
and  butterfat  they  produced.  The  record  of  the  cows  from  five  of  the 
herds  together  with  the  cost,  at  the  market  price  of  feed,  of  the  milk  and 
butterfat  produced  by  the  different  cows  in  exactly  one  year  is  given  in 
Table  36. 

TABLE  36. — BEST  AND  WORST  Cows  IN  FIVE  HERDS  (FRASER) 


Number  of  cow 

Pounds  of  milk 

Pounds  of  fat 

Cost  per  100  Ib. 
of  milk 

Cost    per    1    Ib.    of 
butterfat 

83 

11,794 

382.4 

$0.61 

$0.19 

84 

8,157 

324.0 

0.87 

0.21 

85 

9,592 

406.3 

0.75 

0.18 

86 

3,098 

119.2 

1.56 

0.40 

93 

9,473 

358.6 

0.76 

0.20 

94 

7,846 

282.1 

0.87 

0.21 

95 

14,841 

469.0 

0.56 

0.18 

96 

7,686 

324.1 

0.80 

0.22 

97 

8,563 

291.0 

0.78 

0.23 

98 

1,411 

52.8 

2.77 

0.74 

By  comparing  the  amount  of  milk,  of  fat  and  the  cost  thereof,  the 
difference  in  the  earning  capacity  of  the  several  cows  is  shown  in  a  striking 
manner.  The  best  cow  of  all  produced  over  10  times  as  much  milk  as 
the  poorest  cow  and  produced  it  at  56  cts.  per  100  Ib.,  in  marked  contrast 
to  the  $2.77  required  by  the  poorest  cow  to  produce  the  same  amount. 

Cow-testing  Associations. — In  order  that  farmers  may  rid  their  herds 
of  unprofitable  animals  cow-testing  associations  have  been  formed.  The 
idea  was  originated  by  a  woman  in  Denmark  and  after  3  years  of  agitation 
resulted  in  the  formation  of  the  first  association  on  May  1,  1905.  The 
idea  spread  to  all  of  the  principal  dairying  countries  of  the  world. 

The  Newaygo  County  Dairy  Testing  Association  of  Fremont,  Mich., 
founded  by  Helmer  Rabild,  was  the  first  in  the  United  States.  In  4 
years  it  increased  the  average  fat  yield  of  all  its  cows  49.5  Ib.  The  asso- 
ciations are  generally  organized  by  dairymen  acting  in  cooperation  with 
the  State  Experiment  Station,  the  farmers  usually  paying  so  much  per 
cow  to  become  members  and  agreeing  to  do  certain  things,  such  as  to 
carry  the  tester  to  the  next  farm,  etc.  The  station  supplies  the  tester 
who  is  often  a  student  working  under  the  direction  of  a  more  experienced 
man.  The  tester  not  only  does  the  particular  work  for  which  he  is  hired 
but  interests  the  members  of  the  association  in  better  methods  of  feed- 
ing and  caring  for  the  herd  and  in  other  matters  pertaining  to  the  farm 


DAIRY  CATTLE  AND  THE  DAIRY  FARM 


115 


on  which  advice  is  needed.     The  tester's  salary  and  the  expense  of  the 
materials  used  are  defrayed  by  the  money  paid  by  the  farmers. 

In  Table  37  are  given  some  results  obtained  at  a  few  associations  in 
different  parts  of  the  Union. 

TABLE  37. — MILK  AND  BUTTERFAT  PRODUCTION,  PERCENTAGE  OP  FAT,  COST  OF 

FEED  AND  RANGE  OF  VARIATION  IN  PRODUCTION  AND  COSTS  AS  DETERMINED 

BY  A  FEW  COW-TESTING  ASSOCIATIONS 


Association 

Year 

Number  of 
herds 

Herd  average 

Range  of  variation 

Number  of 
cows 

Amount  of 
milk 

"8 
1 

1 

Fat  test,  per 
cent. 

Value  of  feed 

3 

i 

o 

1 

Fat  Ibs. 

Value  of 
feed 

Feed  cost 
fat 

1 

Worst 
cow 

"S  o 

0)   o 

*> 

Is 

1? 

1* 

York-Fairhaven,  111... 
Dickinson         County, 
Kansas 

1911-12 

1909-10 
1909-10 

1911-12 

1907  & 
1908 

1911-12 

1909 

24 

19 
23 
23 

26 
5 

12 

26 
8 

262 

134 
337 
351 

498 
701 

298 

326 
581 

48 

50 
55 
50 

68 
41 

44 

65 
59 

188 

246 
232 
180 

251 
179 

217 

244 
251 

4.0 

4.1 
4.2 
3.6 

4.0 
4.5 

4.8 

3.8 
4.2 

$35.00 

35.59 
36.25 
32.14 

38.44 
38.  602 

29.75 
73.03 

$0.18 

0.14 
0.16 
0.18 

0.15 
0.22i 

0.14 
0.30 

362 

546 
413 
321 

446 
351 

411 

464 
627 

75 

59 
64 
75 

72 
118 

65 

40 
83 

$40 

56 
32 
45 

47 
44 

37 
107 

$32 

33 
35 
24 

29 
32 

24 
45 

$0.11 

0.10 
0.08 
0.14 

0.10 

0.132 

0.24 
0.23 

$0.42 

0.56 
0.21 
0.32 

0.39 
0.262 

0.37 
0.74 

Pioneer   Iowa 

Benson,  Iowa  
Richmond-Lewiston, 
Utah 

Blacksburg,  Virginia  .  . 
Tennessee 

Lyndeboro,         New 
Hampshire  
Ferrisdale,  California.. 

1  Six  did  not  complete  test. 

2  Cost  of  food  and  labor  less  value  of  manure. 

Sheltering  Cattle. — Proper  shelter  for  the  cattle  is  important.  In 
regions  experiencing  little  severe  weather  hardly  more  is  required  than  a 
simple  structure  giving  the  animals  protection  from  inclement  weather 
and  particularly  against  wet  chilling  storms,  but  in  cold  climates  housing 
is*a  more  serious  matter  for  the  herd  is  confined  almost  continuously 
for  15  weeks  or  more.  Stabling  becomes  a  question  not  merely  of  afford- 
ing temporary  protection  to  the  cattle  but  primarily  of  providing  them  a 
home.  Indeed  the  barn  is  even  more  than  this  for  it  is  the  place  where 
the  business  of  feeding  the  animals,  milking  them  and  developing  them  is 
carried  on.  So  it  is  necessary  to  provide  for  the  needs  of  the  cattle,  the 
convenience  of  the  laborers  and  such  conditions  that  milk  can  be  drawn 
and  handled  without  unduly  exposing  it  to  deteriorating  influences. 
Furthermore,  the  business  carried  on  in  the  barn  is  part  of  the  business 
of  the  farm  considered  as  a  whole,  consequently  it  should  be  operated  in  a 
way  and  from  a  place  that  makes  it  fit  in  well  with  other  farm  work;  the 
location  of  the  barn  is  important. 

Barn  building  involves  the  choice  of  the  type  of  barn  best  adapted 
to  the  farm  and  to  the  site.  The  barn  should  be  arranged  in  such  a  way 
as  to  save  work  and  it  ought  to  be  well-lighted,  warm  and  ventilated. 


116  CITY  MILK  SUPPLY 

Construction  should  be  undertaken  in  a  conservative  spirit  and  only 
after  careful  planning  for  the  present  needs  of  the  herd  and  with  some 
foresight  as  to  its  probable  growth  and  the  demands  of  the  future.  At 
the  outset  it  is  most  important  to  realize  that  the  outlay  called  for,  consti- 
tutes a  fixed  charge  on  the  business,  yet  many  dairyman  fail  to  grasp  the 
fact.  Money  invested  in  a  dairy  barn  should  pay  10  per  cent,  a  year. 
So  on  a  barn  costing  $1,000  and  housing  20  cows  there  is  a  fixed  charge 
of  $5  a  head,  a  sum  that  at  3.8  cts.  a  quart  will  take  the  sale  of  131.5  qt.  of 
milk  from  every  cow  to  raise,  which  in  most  instances  is  excessive.  The 
inevitable  consequence  of  erecting  too  costly  a  barn  is  to  lay  a  tax  on  the 
business,  that  the  cows  cannot  pay  off.  Were  they  asked,  the  health 
officers  of  our  large  towns  could  point  out  many  dairymen  who  have  seri- 
ously curtailed  their  profits  by  investing  too  heavily  in  barn  buildings. 
On  the  other  hand,  a  good  barn  pays  because  the  herd  is  made  more 
comfortable  and  therefore  more  productive,  the  help  better  satisfied  and, 
consequently,  more  efficient,  and  labor  is  expedited  and  made  less  costly 
because  of  careful  planning  and  the  introduction  of  devices  that  save  toil. 
Dairymen  owe  it  to  themselves  and  to  their  trade  to  exercise  good  judg- 
ment in  deciding  how  much  capital  they  will  invest  in  the  barn  and  what 
sort  of  building  it  shall  be. 

Types  of  Barns. — Rarely  is  much  consideration  given  as  to  what  type 
of  building  is  best  adapted  to  the  business  for  there  is  a  strong  tendency 
to  build  in  the  style  of  the  district.  While  it  is  true  that  this  style  may 
have  been  settled  on  as  the  result  of  some  experimenting  with  other  types, 
more  often  it  has  become  the  fashion,  simply  as  the  result  of  thoughtless 
copying. 

Broadly  speaking,  there  are  but  two  types  of  barns,  rectangular  and 
round  barns  for  under  these  two  all  sorts  of  barns  may  be  grouped  thus : 

1.  Rectangular  barns: 
Three-story  or  basement  barns. 
Two-story  or  loft  barns. 
One-story  or  shed  barns. 
Double  stabling  barns. 

2.  Round  barns. 

Basement  Barns. — In  this  country,  in  some  places,  particularly  in  the 
older  dairy  sections  that  are  hilly,  barns  with  basement  stables  are  com- 
mon. The  objections  to  them  are  serious.  The  basements  are  often 
poorly  drained,  and  they  are  generally  built  into  the  bank  of  the  knoll 
on  which  the  barn  stands,  in  such  a  way  as  to  entirely  cut  off  the  light  and 
air  from  the  cattle  on  two  or  three  sides.  So  these  stables  are  dark,  damp, 
malodorous  and  of  ten  very  hot  in  summer.  The  second  floor  is  commonly 
used  for  horses  and  implements  while  on  the  third  are  the  hay  mows. 

Loft  Barns. — The  loft  barn  is  a  good  style  for  general  farming.  The 
walls  are  all  above  ground.  The  animals  are  kept  on  the  ground  floor 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  117 


FIG.  13. — Basement  barn,  Sparks,  Maryland. 


Courtesy  of  W.  J.  Eraser. 

FIG.  14. — Interior  of  an  Illinois  basement  barn. 


118 


CITY  MILK  SUPPLY 


FIG.  15. — A  Maryland  loft  barn. 


FIG.  16. — A  Missouri  loft  barn. 


Courtesy  of  Robert  Burnett. 

FIG.  17. — Loft  and  shed  barns  of  Deerfoot  Farms,  Southboro,  Mass. 


Courtesy  of  C.  W.  Eddy. 

FIG.  18. — Shed  barn  of  the  Municipal  Dairy,  Cleveland  Ohio. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  119 

and  the  feed  is  stored  above  them.  These  barns  should  be  well-lighted, 
usually  from  two  sides  and  an  end  at  least;  should  have  a  ventilating 
system  and  the  first  floor  should  be  ceiled  off  from  the  second  so  as  to 
prevent  dust  from  sifting  down  from  above. 

Shed  Barns. — Shed  barns  can  be  easily  enlarged  and  kept  clean.  So, 
in  their  most  modern  form  they  represent  the  latest  development  in 
cattle  housing  on  farms  where  great  attention  is  paid  to  the  production 
of  sanitary  milk.  In  warm  climates  shed  barns  with  siding  only  part 
way  up  are  used,  thus  giving  all  necessary  protection  and  at  the  same  time 
being  cool  and  having  plenty  of  light  and  air.  In  some  cases  canvas 
curtains  are  provided  to  give  additional  protection  from  the  elements 
when  necessary.  In  California  a  form  of  shed  barn  known  as  the  saw- 
tooth barn  is  popular. 


Courtesy  of  the  DeLaval  Separator  Co. 

FIG.  19. — Saw-tooth  dairy  barn  at  Oakley,  California. 

Double  Stabling  Barns. — Double  stabling  barns  are  used  in  this  way. 
The  cattle  are  turned  loose  in  what  is  often  a  reconstructed  farm  building 
or  perhaps  a  low  roughly  built  structure  that  has  a  dirt  floor  and  a  galvan- 
ized-iron  or  other  inexpensive  roof  of  some  sort.  Here  the  animals  are 
fed  their  roughage  and  sometimes  part  of  their  grain.  Watering  troughs 
are  placed  so  that  the  animals  can  drink  whenever  they  want  to.  The 
cows  are  fed  their  grain  and  milked  in  another  building  which  should  be 
large  enough  to  hold  a  third  of  the  herd  that  milking  may  be  done  ex- 
peditiously  and  which  is  so  built  that  clean  milk  may  be  easily  produced 
therein.  Directly  after  milking,  the  cattle  are  turned  back  into  the  other 
barn.  This  system  avoids  dust  from  bedding  and  provender,  and  since 
the  cows  are  in  the  milking  stable  but  a  short  time,  it  is  kept  clean  and 
sweet.  Besides  these  advantages  the  covered  barnyard  system  gives  the 
cows  freedom  of  exercise  at  will  and  makes  economical  handling  of  the 
manure  possible  for  it  can  be  allowed  to  accumulate  till  work  is  slack 
when  it  can  be  carted  right  onto  the  land.  An  objection  to  the 
system  is  that  twice  the  usual  amount  of  bedding  is  required  to  keep  the 
cows  clean. 


120 


CITY  MILK  SUPPLY 


Combination  Barns. — Combination  barns  for  cows  and  horses  are 
used  in  some  places.  They  are  usually  the  property  of  men  who  own  little 
stock  or  of  gentlemen  farmers  who  keep  cows  for  their  own  convenience 
and  that  of  their  neighbors.  They  have  the  advantage  of  enabling  the 
saving  of  labor  but  they  are  difficult  to  clean,  are  likely  to  be  infested  with 
flies  because  of  the  horse  dung  that  accumulates  and  often  derive  pungent 
odors  from  the  horses  and  their  droppings  that  taint  the  milk.  Generally 
boards  of  health  forbid  the  production  of  milk  for  sale,  in  such  barns  unless 
a  solid  wall — often  brick  or  concrete  is  demanded — separates  the  two 
classes  of  stock. 


FIG.  20. — Basement  stable  and  milk 
house,  Washington,  D.  C. 


FIG.  21. — A  New  Jersey  loft  barn. 


FIG.  22.— Shed  barn  of  the  U.  S.  Naval 
Academy. 


FIG.  23. — A  shed  barn  and  a  loft  barn  of 
the  Fairneld  Dairy  Co.,  Caldwell,  N.  J. 


FIG.  24. — Double  stabling  barn  of  the     FIG.  25. — Round  barns  of  the  University 
Maryland     Agricultural     Experiment  of  Illinois. 

Station. 

Round  Barns. — Round  barns  are  strong  and  cheaper  to  build  than 
rectangular  plank  frame  barns.  The  silo  helps  to  support  the  roof  and 
is  protected  by  the  barn;  being  centrally  located,  it  is  easy  to  feed 
from,  and  the  silo  chute  assists  in  ventilating  the  barn.  It  is  easy  to 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  121 

handle  hay  in  the  mows  for  they  are  unobstructed.  The  objections 
raised  to  the  round  barns  are :  that  they  cannot  be  enlarged  if  the  growth 
of  the  herd  demands  it,  that  they  are  difficult  to  light,  that  rectangular 
objects  cannot  be  stored  conveniently  and  that  much  space  is  wasted  in 
the  driveway. 

Barn  Construction. — The  construction  of  a  barn  should  be  simple 
that  it  may  be  easily  kept  in  sanitary  condition  and,  except  where  the 
building  is  frankly  temporary  in  character,  it  should  be  substantial.  The 
foundation  maybe  either  of  cement  or  of  masonry  set  in  cement,  and  should 
always  rise  far  enough  above  the  ground  to  prevent  moisture  from  rotting 
the  sills  and  frame.  Indeed,  it  is  best  to  run  the  foundation  up  to  the 
bottom  of  the  window  sills.  Either  a  mortised  timber  or  plank  frame 
may  be  used.  The  former  is  the  older  and  commoner  way  of  framing; 
the  latter  is  the  modern  way  and  has  come  into  vogue  because  it  is  cheaper, 
stronger  and  more  easily  and  quickly  built.  Both  ways  of  framing  may  be 
done  in  such  a  manner  as  to  admit  of  either  horizontal  or  of  vertical  siding. 
The  walls  should  be  windproof  and  as  smooth  as  possible.  In  mild 
climates  a  single  solid  wall  is  warm  enough,  but  in  cold  climates  double 
walls  with  an  air  space  between  them  are  necessary.  Either  a  gable  or  a 
gambrel  roof  may  be  used;  the  latter  is  self-supporting  and  gives  ample 
loft  room.  Floors  should  be  durable  and  impervious  to  water  so  that  they 
may  be  non-absorptive  and  flushed  frequently.  They  should  be  sloped 
slightly  toward  the  gutters. 

The  standard  width  of  barns  is  36  ft. ;  they  are  usually  built  in  bents 
either  10  or  14  ft.  long,  the  former  providing  for  three,  and  the  latter  for 
four,  stalls  between  posts.  The  barn  should  be  laid  out  so  as  to  provide 
platforms  and  gutters  for  the  cows,  feeding  alleys,  cleaning  alleys,  a  box 
stall  for  calving,  bull  pens,  calf  pens,  a  milk-room,  and  office  for  the 
herdsman  and  a  dressing  room  for  the  help. 

Necessity  of  Good  Planning. — A  little  scientific  management  needs 
to  be  applied  to  the  problems  of  the  dairy  barn  and  provision  made  for 
the  conservation  of  energy.  Fraser  of  the  Illinois  Station  illustrates  the 
unnecessary  labor  that  bad  planning  entails,  by  supposing  a  milk-room  to 
be  located  50  ft.  farther  than  need  be  from  the  cows,  and  calculating  that 
the  milker  in  carrying  the  milk  back  and  forth,  would  cover  12  rods  per 
cow  each  day,  which  in  a  herd  of  60  cows  would  mean,  2J4  miles  extra 
travel  a  day,  or  in  a  year,  164  extra  miles  for  each  milker. 

Plan  of  Round  Barn. — The  round  barn  should  not  be  much  less  than 
60  ft.  in  diameter  and  it  is  not  economy  to  have  it  much  larger.  It  is 
arranged  in  a  series  of  concentric  circles  formed  by  the  silo,  mangers, 
curbing,  stalls,  gutters  and  alley. 

Plan  of  Rectangular  Barn.- — A  rectangular  dairy  barn  may  be  arranged 
in  either  of  two  ways.  The  cows  usually  stand  in  two  rows  and  according 
to  one  arrangement,  the  cows  face  out,  while  in  the  other  they  face  in. 


122  CITY  MILK  SUPPLY 

Both  methods  have  ardent  advocates.  The  principal  advantage  claimed 
for  heading  the  cows  outward  is  that  it  makes  the  handling  of  the  manure 
easy,  for  a  cart  or  manure  spreader  can  be  driven  down  the  cleaning 
alley  and  loaded  from  the  gutters  at  each  side.  Also,  this  mode  of  sta- 
bling shows  off  the  cows  to  visitors  best.  The  advantage  of  heading  the 
cows  inward  are:  (1)  feeding  is  more  easily  done  with  the  feed  alley  in  the 
middle  of  the  barn;  (2)  the  gutters,  being  near  the  windows,  have  direct 
sunlight ;  (3)  the  light  falls  on  the  rear  quarters  of  the  animals,  making  it 
easy  to  clean  the  animals  and  stalls,  and  to  milk;  (4)  there  is  less  confusion 
in  letting  the  cows  in  and  out;  (5)  the  supporting  posts  can  be  placed  in  the 
line  of  the  head  rail  which  is  at  the  narrowest  part  of  the  cow,  thereby 
saving  room.  An  objection  to  this  arrangement  is  that  the  walls  are  likely 
to  be  splashed  with  dung  and  consequently  to  need  careful  attention. 

In  barns  where  the  cows  are  headed  out  the  cleaning  alley  forms  a 
driveway  down  the  middle  of  the  barn,  and  parallel  on  each  side  in  suc- 
cession toward  the  wall  is  placed  a  gutter,  a  platform,  a  row  of  mangers 
and  a  feeding  alley.  The  driveway  is  9  ft.  wide,  the  gutters  are  16  in. 
wide,  10  in.  deep  next  the  platform  and  4  in.  deep  next  the  alley; 
they  should  pitch  1  in.  in  20  ft.  toward  the  lower  end  of  the  stable. 
The  platforms  are  5  ft.  wide.  The  rear  partition  of  the  mangers  at  the 
front  of  the  platform  is  6  in.  wide.  The  manger  is  3  ft.  wide  with  the  top 
30  in.  from  the  floor.  The  feed  alley  is  3  ft.  4  in.  wide. 

In  barns  where  the  cows  face  inward,  a  feed  alley  6  ft.  wide  runs  length- 
wise down  the  middle  of  the  barn,  then  in  succession  toward  each  wall 
and  of  the  same  dimensions  as  where  the  cows  face  outward,  come  the 
mangers,  the  platforms  and  the  gutter,  leaving  a  space  of  4  or  5  ft.  for  the 
cleaning  alley  between  the  gutter  and  the  wall. 

Barn  Floor. — Some  of  the  details  of  construction  should  engage  atten- 
tion. The  floors  are  sometimes  of  earth  but  they  are  usually  either  of 
wood  or  of  concrete.  Dirt  floors  are  permitted  only  where  the  most  primi- 
tive conditions  obtain.  They  are  insanitary  because  they  cannot  be 
kept  clean,  and  they  are  objectionable  because  the  larvae  of  flies  breed  in 
them.  The  most  wretched  are  those  without  gutters;  those  with  concrete 
gutters  having  the  cement  work  carried  forward  beneath  the  cows  far 
enough  to  catch  the  urine  are  more  decent.  The  first  cost  of  wooden 
floors  is  generally  less  than  that  of  cement  ones  but  they  are  shorter  lived; 
the  length  of  service  they  give  is  dependent  on  the  way  they  are  built. 
They  last  longest  either  laid  in  contact  with  the  earth  so  that  moisture  is 
constantly  retained  or  laid  so  as  to  admit  free  circulation  of  air  below. 
Under  such  conditions  they  possibly  may  last  6  to  10  years  but  where  they 
are  laid  so  that  there  is  not  sufficient  air  space  below  to  admit  free  circu- 
lation of  air  they  wear  out  in  3  to  5  years.  Wooden  floors  are  objection- 
able because  they  absorb  urine  and  become  foul-smelling.  Concrete 
floors  are  best;  they  commonly  have  a  thickness  of  4  in.  of  grout  and  a 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  123 

1-in.  facing.  .The  grout  may  be  laid  by  ordinary  farm  labor  but  the  facing 
should  be  done  only  by  a  skilled  workman.  The  floors  should  be  rounded 
up  at  the  walls  and  in  the  corners  to  prevent  dust  accumulating  in  the 
joints  and  to  facilitate  cleaning. 

Platforms. — The  platform  should  have  a  pitch  toward  the  gutter  of  1 
in.  in  5  ft.  It  should  be  built  of  impervious  material;  concrete  is  generally 
used.  It  should  be  finished  rough  as  with  a  board  trowel  to  prevent  the 
cows  slipping.  A  depression  in  front  of  the  tie,  14  in.  wide  and  1J^  in. 
deep  tends  to  keep  the  bedding  in  place,  makes  the  cow  stand  more  nearly 
level  and  prevents  her  slipping  when  reaching  in  the  manger  for  feed. 
An  objection  to  concrete  is  that  it  is  a  good  conductor  of  heat  and  so  tends 
to  chill  the  cows,  producing  stiffness  and  udder  inflammation.  This  may 
be  quite  overcome  by  the  use  of  bedding  or  by  placing  a  slatted  rack 
over  the  concrete  or  by  a  movable  floor  about  3  ft.  wide  that  is  kept  in 
place  by  two  iron  pins  set  in  the  concrete  near  the  corners.  If  such  floors 
are  used  they  should  be  removed  often  for  cleaning  beneath  them;  in 
summer  they  are  unnecessary.  Vitrified  brick,  laid  on  a  cement  founda- 
tion and  set  in  cement,  is  sometimes  used  for  a  platform  and  for  floors. 
The  same  objections  lie  against  it  as  against  cement.  The  shortcomings 
of  concrete  have  led  to  the  use  of  cork  brick  and  creosoted  wood  blocks 
for  flooring.  They  are  costly  and  somewhat  expensive  to  put  down,  for 
they  are  set  in  cement  and  laid  on  a  cement  base.  They  are  not  easily 
cleaned  but  they  are  not  cold  and  are  easy  on  the  feet  of  the  animals. 

Alignment  of  the  Animals. — Aligning  the  cows  on  the  platform  re- 
quires some  planning.  The  standard  width  of  the  stall  is  3  ft.  6  in.  The 
length  of  a  stall  for  a  Jersey  should  be  from  4  ft.  4  in.  to  4  ft.  10  in.  and  for 
a  Holstein  from  4  ft.  8  in.  to  5  ft.  2  in. ;  the  stalls  for  other  common  breeds 
fall  between  these  extremes.  If  the  stall  is  too  long  the  droppings  will 
fall  on  the  platform,  while  if  it  is  too  short  the  cows  will  stand  in  the 
gutter  and  in  either  case  soil  themselves.  There  are  three  ways  of  meet- 
ing this  difficulty.  One  is  to  make  the  platform  on  one  side  of  the  barn 
5  ft.  wide  and  on  the  other  4  ft.  6  in. ;  a  second  is  to  make  the  platform 
4  in.  wider  at  one  end  than  at  the  other  with  a  gradual  slant  between 
them;  and  the  third  is  to  use  adjustable  stanchions  which  may  be  set 
back  3  or  4  in.  from  the  support  for  the  short  cows  or  ahead  a  like  amount 
for  the  long  ones. 

Stall  Partitions. — Stall  partitions  are  not  strictly  necessary  but  are 
considered  desirable  by  most  dairymen.  Wooden  partitions  are  thor- 
oughly objectionable  because  they  become  foul,  are  difficult  to  keep  clean 
and  detract  from  the  appearance  of  the  barn.  Curved  iron  piping  1%  in. 
in  diameter  makes  the  best  partitions  and  needs  be  little  more  expen- 
sive than  wood. 

Gutters. — The  gutters  are  probably  more  often  botched  in  building, 
than  any  other  part  of  the  dairy  barn,  the  tendency  being  to  make  them 


124  CITY  MILK  SUPPLY 

too  shallow  and  to  give  them  too  little  pitch.  They  should  be  18  in. 
wide  with  vertical  sides  10  in.  deep  next  the  platform  and  4  in.  deep  next 
the  alley;  they  should  have  a  slope  of  from  2  to  3  in.  in  every  40  ft.  The 
gutters  should  be  built  of  cement  for  sanitary  reasons  and  to  conserve 
all  the  fertility  of  the  manure.  The  gutter  should  terminate  in  a  6-in. 
sewer  pipe,  the  mouth  of  which  should  be  covered  with  a  solid  top  except 
when  the  stable  is  being  washed  out,  when  a  perforated  top  should  be 
substituted.  A  bell  trap  may  be  used  to  stop  the  nuisance  that  results 
from  choking  of  the  pipe  with  straw.  The  pipe  should  lead  the  liquid 
manure  to  a  water-tight  cesspool  from  which  it  is  pumped  and  sprinkled 
on  the  land  as  needed. 

Alleys. — The  alleys  should  be  sloped  gently  toward  the  gutters. 

Walls. — The  walls  of  the  barn  next  the  alleys  should  be  plastered  with 
cement  from  the  floor  to  the  window  sills  that  spattered  droppings  may  be 
easily  cleaned  off. 

Stanchions. — There  are  several  sorts  of  stanchions.  The  old-fash- 
ioned rigid  stanchion  had  the  advantage  of  keeping  the  cows  clean  but 
as  it  did  not  give  enough  freedom  of  movement  to  the  cows  nor  permit 
them  to  lie  in  a  natural  position  it  has  been  largely  superseded  by  those 
that  give  these  advantages.  The  swing-chain  stanchion  has  proved  the 
most  popular.  Stanchions  are  made  either  of  wood  or  iron  pipe;  the 
latter  is  comfortable  for  the  cattle  and  is  more  durable  than  the  former. 
These  stanchions  may  be  purchased  at  about  $1.35  a  piece  and  put  up  at 
home.  They  are  hung  from  wooden  framework  or  better  from  a  frame- 
work of  gas  piping  set  in  cement.  The  double-post  slip-chain  stanchion 
is  comfortable  and  seems  to  be  coming  back  into  use. 

Mangers. — Mangers  in  a  few  barns  are  dispensed  with,  feeding  being 
done  right  on  the  floor.  This  practice  is  uncommon,  most  dairymen 
using  mangers  of  which  there  are  many  styles  and  which  are  built  of 
different  materials.  Wooden  mangers  were  once  practically  universally 
used  but  they  are  being  rapidly  displaced  because  food  gathered  in  the 
cracks  making  them  sour  and  ill-smelling.  Metal  mangers  are  used  but 
cannot  be  recommended  because  they  lack  durability.  Cement  mangers 
have  proved  the  most  popular;  they  are  usually  built  in  trough  form  which 
makes  them  easy  to  wash  out.  They  should  be  3  ft.  wide.  The  bot- 
tom should  be  rounded  and  should  be  1  or  2  in.  above  the  platform;  and 
the  walls  should  be  smooth  and  should  rise  18J4  to  30  in.  above  the 
floor.  The  objections  are  raised  to  trough  mangers  that  the  cows  rob 
one  another  of  food  and  that  tubercular  animals  readily  spread  infection 
in  them.  The  first  difficulty  is  met  by  providing  metal  partitions  that 
can  be  dropped  into  place  at  feeding  time  and  raised  thereafter.  As  to 
the  second  its  truth  may  be  admitted,  but  there  are  so  many  ways  for 
the  tubercular  animal  to  spread  infection  that  it  seems  hopeless  to 
prevent  her  doing  so  as  long  as  she  is  a  member  of  the  herd.  Remov- 
ing her  therefrom  is  the  only  remedy. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  125 

Milk  Room. — The  milk  room  is  a  highly  valuable  appurtenance  of  the 
dairy  barn.  In  even  the  smallest  dairies  some  sort  of  a  separate  room 
should  be  provided  for  the  cans  into  which  the  milk  is  poured  from  the 
milkers'  pails.  This  is  necessary  because  milk  absorbs  odors  very  readily 
and  if  it  stands  exposed  in  the  stable  it  is  sure  to  acquire  a  more  or  less 
decided  taint.  The  "cowy"  flavor  of  milk,  to  which  so  many  object,  is 
taken  on  in  the  stable  and  is  in  reality  derived  from  the  manure  rather 
than  the  cows.  Dairymen  doing  a  considerable  business  need  a  good 
milk  room.  It  should  be  conveniently  located,  easy  to  enter  and  leave, 
airy,  well-lighted  and  large  enough  for  the  milkers  to  use  without  crowd- 
ing. In  it  the  milk  is  weighed,  sampled  and  strained  and  the  milk  records 
posted.  In  summer  it  should  be  thoroughly  screened. 

Office. — There  should  be  an  office  for  the  herdsman  where  he  can  put 
his  books,  file  his  records,  keep  the  medicines  and  the  instruments  such 
as  milk-tubes,  teat-openers  and  the  like  that  should  rightfully  be  in  his 
charge. 

Dressing  Room. — The  dressing  room  for  the  help  should  be  light  and 
should  be  provided  with  a  bench,  mirror,  lockers  for  the  clothes  and,  if 
running  water  is  available,  with  open  plumbing,  otherwise  hand  basins 
must  be  used.  Individual  or  paper  towels  should  be  supplied;  the  roller 
towel  is  as  insanitary  in  the  dairy  barn  as  it  is  anywhere  else.  The 
dressing  room  including  the  lockers  should  be  inspected  for  cleanliness 
often.  In  barns  too  small  to  afford  a  dressing  room,  the  herdsman's 
office  may  be  used  for  this  purpose. 

Ceiling. — Except  in  certain  types  of  shed  barns  it  is  necessary  to  care- 
fully ceil  the  part  of  the  stable  where  cows  are  kept  in  order  to  prevent 
dirt  from  sifting  down  from  above.  The  ceiling  should  not  be  more  than 
9  ft.  above  the  floor  and,  except  where  wagons  are  to  be  driven  into  the 
barn,  a  clearance  of  7  ft.  6  in.  between  the  floor  and  bottom  of  the  ceiling 
joists  is  sufficient.  Stables  of  greater  height  are  apt  to  be  cold  because 
the  animal  heat  is  likely  to  be  insufficient  to  warm  them.  Moreover  they 
are  apt  to  be  draughty  and  in  some  there  is  a  tendency  for  air  to  stagnate 
at  the  top. 

Lighting. — The  lighting  of  a  barn  'demands  careful  attention.  Until 
recently  dairy  barns  were  dark  or  at  best  poorly  lighted.  Now  it  is  gen- 
erally recognized  that  plenty  of  light  is  necessary  for  the  comfort  of  the 
animals,  to  reduce  eyestrain  among  the  employees,  to  facilitate  work 
and  to  produce  a  cheerful  atmosphere.  Also,  it  is  known  that  sunlight 
tends  to  enfeeble  and  to  destroy  germ  life.  The  amount  of  light  needed 
in  a  dairy  barn  has  not  been  definitely  determined  either  by  experiment 
or  practice,  but  4  sq.  ft.  of  window  space  per  animal  or  a  minimum  of 
2  sq.  ft.  per  500  cu.  ft.  of  air  space  is  believed  to  be  right  and  emphasis  is 
laid  on  the  fact  that  the  windows  must  be  so  placed  that  the  light  is  evenly 
distributed.  A  barn  with  the  light  all  at  one  end,  or  one  lighted  so  as  to 


126  CITY  MILK  SUPPLY 

produce  a  blotched  effect,  is  unsatisfactory.  In  placing  the  windows  it 
should  be  borne  in  mind  that  the  barn  is  lighted  both  by  direct  sunlight 
and  by  reflected  light  from  the  sky. 

Ventilation. — Despite  the  vast  amount  of  study  that  has  been  given 
to  ventilation  much  is  yet  to  be  learned  about  it  and  about  the  effect  of 
poor  ventilation  on  health  so  that  dogmatic  opinions  in  these  matters  are 
out  of  place.  Researches  now  under  way  may  considerably  modify  our 
present  beliefs.  The  ventilation  of  dairy  barns  is  highly  important. 
The  objects  are  to  provide  for:  (1)  the  well-being  of  the  herd;  (2)  the 
comfort  of  the  workmen;  (3)  the  removal  of  odors  likely  to  impart 
bad  flavors  to  this  milk;  (4)  the  carrying  off  of  moisture  transpired  by 
the  animals,  before  it  has  a  chance  to  condense  on  the  barn  and  rot  it. 
The  lighting,  ventilating  and  heating  of  a  barn  are  related  problems,  in 
fact  so  closely  so,  that  it  is  generally  true  that  what  affects  one,  in  some 
measure  does  the  others. 

The  temperature  at  which  dairy  cows  should  be  kept  has  not  been 
determined ;  Eckles  is  of  the  opinion  that  as  suitable  as  any  is  between 
40°  and  50°F.,  while  King  thinks  it  likely  that  for  animals  being  fed  high 
45°  to  50°F.  is  best,  that  those  on  a  maintenance  ration  will  do  better  and 
at  lower  cost  at  temperatures  between  55°  and  65°F.  To  warm  barns, 
reliance  is  usually  placed  on  the  heat  given  off  by  animals  themselves. 

Ventilation  by  Windows. — Satisfactory  ventilation  can  be  secured 
from  windows  if  there  are  enough  of  them  and  if  they  are  properly  disposed ; 
they  should  be  placed  well  up  the  wall  usually  with  the  bottoms  of  the 
frames  at  the  level  of,  or  somewhat  higher  than,  the  backs  of  the  cattle  and 
they  should  be  set  flush  with  the  wall  that  there  may  be  no  ledge  whereon 
dust  may  settle.  It  is  best  to  have  them  pivoted  at  the  middle  of  the  sides 
of  the  window  so  that  they  can  be  tipped  inward  leaving  openings  at  the 
top  and  bottom.  It  is  almost  as  good  to  have  them  hinged  at  the  bottom 
so  that  they  can  be  opened  inward  at  the  tops  and  so  admit  the  air  above 
the  animals.  Windows  that  open  by  sliding  sideways  or  past  each  other 
are  not  so  well  adapted  to  dairy  barns  as  other  styles  are.  When  window 
ventilation  is  practised,  the  hay  and  silage  chutes  serve  as  outlets  for  the 
foul  air. 

The  King  System. — The  system  of  ventilating  dairy  barns  most 
widely  used  in  the  United  States  was  introduced  in  the  summer  of  1889 
by  King  of  the  University  of  Wisconsin  and  is  known  as  the  King  system. 
It  has  the  merits  of  being  efficient,  simple  of  construction  and  not  so 
costly  but  that  most  farmers  can  afford  to  use  it.  The  King  system  has 
been  developed  on  the  theory  that  since  carbonic  acid  gas  is  the  chief 
impurity  in  stables,  and  since  this  gas  is  heavier  than  pure  air,  foul  air  is 
likely  to  be  found  in  largest,  quantities  near  the  floor,  therefore,  outlets 
for  it  are  placed  near  the  floor.  To  be  serviceable  the  system  must 
be  installed  in  a  barn  that  is  tight,  for  the  air  currents  of  a  loosely  built 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  127 

barn  prevent  it  from  working  successfully.  The  circulation  in  and  out 
of  the  building  is  through  specially  constructed  flues.  The  inlets  are 
placed  on  all  sides  of  the  barn  and  take  air  from  the  outside  of  the  build- 
ing, being  located  between  the  walls  if  they  are  hollow  or,  if  they  are  of 
solid  masonry,  through  pipes  and  other  special  contrivances.  The  inlets 
on  the  outside,  open  at  the  level  of  the  window  sill  or  lower,  and  on  the  in- 
side, near  the  ceiling.  This  prevents  the  warm  air  rushing  out  as  it 
would  if  the  inlets  were  carried  straight  through  the  walls,  and  on  the 
inside  allows  the  fresh,  cool,  heavy  outside  air  to  slowly  spread  through 
the  stable  without  causing  drafts.  The  combined  area  of  the  inlets 
should  equal  or  exceed  that  of  the  outlets,  for  air  cannot  leave  the  stable 
faster  than  it  comes  in. 

The  outlets  are  the  vital  part  of  the  King  system  and  so  they  should 
be  built  with  the  greatest  of  care.  Except  where  openings  are  provided 
they  should  be  made  with  permanently  air-tight  walls  that  only  air  from 
the  space  to  be  ventilated  rnay  contribute  to  the  current  passing  through 
them.  They  should  be  of  ample  and  uniform  cross-section  throughout 
their  length;  it  is  the  smallest  section  that  determines  the  capacity  of 
the  duct.  Out-takes  of  circular  or  square  cross-section  are  preferable 
to  long,  narrow  ones  because  there  is  relatively  less  surface  to  cool  the  air 
and  to  make  friction,  hence  there  is  less  loss  of  pressure  and  greater 
flow  of  air.  The  suctional  effect  of  the  wind  and  the  motive  power  for 
ventilation  generated  by  temperature  differences,  increase  with  the  height ; 
but  friction  is  augmented  by  height  as  it  is  also  by  bends  and  its  effect 
in  decreasing  motive  power  must  be  taken  into  account.  The  outlets 
are  located  in  the  line  of  the  stanchions  in  those  barns  in  which  the  cows 
face  outward,  and  against  the  walls  in  those  wherein  the  cows  face  inward. 
The  ducts  are  built  of  wood  because  it  is  a  non-conductor  of  heat,  and  are 
extended  upward  through  the  cupola  or  through  the  roof,  either  right  above 
the  stanchions,  if  built  in  the  stanchion  line,  or  near  the  eaves,  if  built 
against  the  walls.  The  latter  way  is  least  satisfactory  because  it  gives 
the  barn  an  unsightly  appearance,  since  the  ducts  have  to  be  carried  above 
the  ridge  in  order  that  downdrafts  may  not  cause  them  to  draw  faultily. 
At  the  top  the  duct  is  covered  by  a  hood  to  keep  out  rain  and  to  increase 
the  circulation  by  the  passing  of  .air  currents  over  the  top  but  care  should 
be  taken  not  to  put  the  hood  so  close  to  the  top  of  the  outlet  flue  as  to  im- 
pede circulation.  For  several  reasons  the  outlets  exhaust  near  the  floor. 
First,  by  doing  so  they  effect  the  greatest  movement  of  air  possible  with 
the  maintenance  of  proper  temperatures.  Second,  by  taking  air  at  this 
level  they  tend  to  promptly  remove  odors  of  the  animals  and  of  the  manure ; 
they  also  draw  out  the  breathed  air  somewhat  directly  because  on  being 
exhaled  from  the  lungs  it  is  cooled  to  about.  81°F.,  at  which  temperature, 
on  account  of  its  carbon  dioxide  content,  it  is  heavier  than  the  surrounding 
air  and  tends  to  sink.  Third,  since  it  is  the  air  of  the  lower  levels  that  is 


128 


CITY  MILK  SUPPLY 


breathed,  it  is  advantageous  to  renew  it  frequently,  and  that,  the  location 
of  the  mouths  of  the  outlets  near  the  floor  accomplishes.  Near  the 
ceiling  the  outlets  are  provided  with  registers  or  intakes  that  are  kept 
closed  in  cool  weather  but  in  hot  are  opened  for  the  double  purpose  of 
cooling  the  barn  and  increasing  the  draft. 

In  small  barns  a  single  large  outlet  flue  is  best;  large  barns  require 
several  of  suitable  size.  King  has  stated  that  a  ventilating  flue  2  by  2  ft. 
through  which  air  moves  at  295  ft.  per  minute  gives  sufficient  air  for 
20  dairy  cows.  However,  he  points  out  that  it  is  the  temperature  in  the 
outlet  flue  that  largely  determines  the  draft  and  that  the  motive  power 
for  ventilation  due  to  temperature,  increases  with  the  height  so  that  this 
factor  should  be  taken  into  account  in  practice  and  he  holds  that  out- 
takes  and  intakes  for  cow  barns  should  provide  for  not  less  than  30  sq. 
in.  per  head,  when  the  out-take  has  a  height  of  30  ft. ;  if  the  out-take  is 
shorter  the  area  should  be  greater,  if  higher  it  may  be  less.  A  20-ft.  out- 
take  should  require  about  36  sq.  in.  per  head  instead  of  30. 

Canadian  Experiments. — Grisdale  and  Archibald  of  the  Dominion 
Experimental  Farms  at  Ottawa  have  made  an  interesting  study  of  the 


t 


IT 


KING  SYSTEM 


Masonry 


Stone  Wall 
Air  Space  and  Wooden 

Lining 

Building  Papers 
ir  Sr>;ire 

RUTHERFORD  SYSTEM 


FIG.  26.—' 


The  King  and  the  Rutherford  systems  of  ventilation.     (From  Bui.  72, 
Dominion  Experimental  Farms.) 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  129 

ventilation  of  farm  buildings.  Their  researches  include  experiments 
with  the  King  system,  The  Rutherford  system,  with  ventilation  through 
pierced  walls,  and  with  ventilation  through  muslin  curtains. 

These  authors  state  that  they  find  the  King  system  unsatisfactory 
in  the  climate  of  Ottawa  and  suggest  that  it  is  better  suited  for  warmer 
countries. 

Rutherford  System. — They  find  that  in  Canada  the  Rutherford 
system  gives  the  best  results.  It  is  built  on  the  theory  that  the  venti- 
lated warm  air  will  rise  in  spite  of  the  high  specific  gravity  consequent 
on  its  high  content  of  carbon  dioxide  gas  and  water.  They  believe 
that  with  the  Rutherford  system  there  is  less  tendency  for  moisture  to 
precipitate  from  the  admixture  of  cold  air  with  moist  warm  air  than 
with  the  King  system.  The  fresh  outside  air  enters  the  stable  at  or  near 
floor  level  through  inlets  that  pass  under  or  pass  through  the  barn  walls 
while  the  foul  air  is  carried  off  through  one  or  more  outlet  ducts  built 
of  boards  running  vertically,  two-ply,  with  an  inch  air  space  and  two 
papers  between  them.  The  air  space  provides  insulation  against  cold 
and  so  prevents  condensation  of  moisture  in  the  duct.  These  ducts 
are  carried  to  the  ridge  of  the  roof  and  are  hooded,  having  15  in.  of  air 
space  between  the  mouth  of  the  duct  and  the  wood.  In  stables  where 
600  to  800  cu.  ft.  of  air  space  is  provided  for  each  cow  2  years  old  and  over, 
there  should  be  15  sq.  in.  or  somewhat  more  of  controlled  outlet  area 
and  8  sq.  in.  or  slightly  more  of  controlled  inlet  area  per  cow.  Controls 
or  dampers  are  needed  because  cold  air,  being  much  heavier  than  warm, 
causes  more  rapid  inflow  and  outflow  of  air  in  very  cold  weather,  than 
in  warm,  making  it  necessary  to  control  the  circulation  to  prevent  barns 
becoming  too  chilly  in  cold  weather  and  too  warm  in  hot. 

The  advantages  claimed  for  the  Rutherford  system  are : 

1.  Ease  of  installation  in  both  old  and  new  buildings. 

2.  Adaptability  to  all  classes  of  stables. 

3.  Suitability  to  variety  of  weather  and  climate. 

4.  Facility  of  operating  and  controls. 

5.  Effectiveness  of  control  of  all  the  stable. 

Ventilation  by  Pierced  Walls. — Ventilation  by  pierced  walls  was  found 
to  be  simple  and  cheap ;  round  or  square  holes  are  pierced  in  all  the  sides 
of  the  stable  exposed  to  outside  air.  In  a  stable  30  by  36  ft.  these  holes 
should  be  4  in.  in  diameter  and  spaced  3  ft.  apart,  or  they  should  be  6  in. 
in  diameter  and  be  placed  6  ft.  apart.  The  holes  may  pass  straight  through 
the  walls  thus  giving  a  direct  current,  or  in  walls  built  with  an  air  space 
a  hole  may  be  placed  on  the  outside  between  the  studs  near  the  ground 
and  one  on  the  inside  a  little  above  the  catties'  backs,  thus  giving  a  de- 
flected current  in  the  space  between  the  walls.  The  air  enters  the  barn 
through  the  holes  on  the  side  exposed  to  the  wind  and  the  stable  air  es- 
capes through  the  other  holes,  consequently  holes  that  on  one  day  serve 


130 


CITY  MILK  SUPPLY 


as  inlets,  on  another,  if  the  direction  of  the  wind  has  changed,  may  serve  as 
outlets.  The  holes  should  have  covers  or  other  devices  for  regulating  the 
passage  of  the  air  in  and  out. 

Ventilation  by  Curtains. — The  efficiency  of  muslin-curtain  ventila- 
tion was  tested  in  a  well-lighted  stable  having  a  ground  floor  of  100  by  25 
ft.  and  a  10-ft.  ceiling.  On  each  side  of  the  building  were  10  windows 
2J^  by  4  ft.  in  area,  located  6  ft.  from  the  floor  and  extending  to  within 
about  18  in.  of  the  ceiling. 

The  advantages  of  the  system  were  found  to  be:  (1)  that  by  taking 
great  care  the  stable  could  be  ventilated  by  means  of  the  muslin;  the 
cheese  cloth  proved  better  than  the  cotton  because  the  air  passed  through 
it  more  easily;  and  (2)  that  this  kind  of  ventilation  is  cheap  and  better 
than  none.  The  objections  to  the  system  are:  (1)  that  great  watchful- 
ness is  required  to  insure  a  fair  measure  of  success;  (2)  there  is  danger  of 
an  excessive  fall  or  rise  of  temperature  during  the  night  on  account  of  a 
rise  or  fall  of  the  wind;  (3)  the  muslin  darkens  the  windows  making  the 
stable  dark,  gloomy  and  damp;  (4)  changing  directions  of  air  currents 
wet  the  muslin  and  prevent  foul  air  escaping  so  that  the  curtains  become 
dirty  and  insanitary. 

Watering  Cows. — Cows  should  be  supplied  with  plenty  of  pure  water. 
It  is  not  safe  to  have  impure  water  on  the  premises  because  some  one  may 
be  made  ill  by  drinking  it,  or  the  milk  may  be  infected  by  it  or  possibly 
the  cows  may  become  infected  with  parasites  through  its  use.  On  the 
small  farms  cows  get  water  in  the  barnyard  or  pasture  but  in  the  larger 
dairies  the  water  is  piped  direct  to  the  mangers. 


Courtesy  of  C.  W.  Eddy. 

FIG.  27. — Manure  trench,  Cooley  Farms,  Cleveland,  Ohio. 

Care  of  the  Manure. — The  conservation  and  handling  of  the  manure 
should  be  carefully  attended  to  by  the  dairy  farmer  because  the  return  of 
its  fertility  to  the  soil  contributes  to  his  financial  success.  A  1,000-lb. 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  131 

cow  voids  approximately  46  Ibs.  of  dung  and  27  Ibs.  of  urine  a  day  which 
together  make  about  12  tons  or  with  bedding  included  about  15  tons 
annually.  Under  proper  management  at  least  80  per  cent,  of  the  fertility 
can  be  returned  to  the  soil.  If  manure  is  to  be  stored,  plenty  of  litter 
must  be  used  and  the  manure  must  be  kept  moist  and  compacted.  To 
prevent  loss  from  leaching  it  must  either  be  protected  by  a  roof  or  kept  in 
a  waterproofed  cement-lined  pit  which  will  retain  all  fluids.  Manure 
cannot  be  stored  without  creating  more  or  less  of  a  nuisance.  It  will 
stink,  it  will  breed  flies  and  unless  unusual  pains  are  taken,  it  will  be  so 
disposed  of  in  the  barnyard  that  the  cows  will  mouth  it,  and  soil  them- 
selves by  walking  through  it  or  by  wading  in  the  puddles  that  are  formed 
by  its  leachings  in  wet  weather.  Manure  is  often  mixed  with  land  plaster, 
thrown  through  a  trap  door  into  the  basement  of  the  barn  and  stored  there. 
It  is  not  a  bad  way  of  keeping  the  manure  but  it  is  attractive  to  flies  and 
rats,  and  is  malodorous  so  that  it  is  offensive,  especially  where  hogs  are 
kept  in  the  manure  in  the  belief  that  they  keep  down  the  stench.  Less 
objectionably,  manure  is  piled  in  sheds  or  lean-tos  some  distance  from 
the  barn.  The  most  wasteful  way  to  keep  manure  is  to  heap  it  under  the 
eaves.  It  has  been  common  for  boards  of  health  to  require  manure  to  be 
removed  a  certain  distance  from  the  barn.  Such  regulations  are  probably 
justified  chiefly  on  the  ground  that  they  lessen  the  likelihood  of  milk  being 
deteriorated  by  odors  but  they  are  not  very  practical  for  it  is  not  where, 
but  how  the  manure  is  kept  that  is  of  importance,  and  they  often  are  the 
cause  of  needless  bickering  between  inspectors  and  owners. 

It  is  best  to  have  some  settled  practice  in  applying  the  manure  to  the 
land.  The  urine  is  the  most  difficult  to  deal  with.  There  are  two  ways 
of  saving  it ;  the  first  is  to  absorb  it  completely  by  the  liberal  use  of  bed- 
ding and  the  second  is  to  lead  it  to  an  underground  waterproofed  cement 
cistern  from  which  it  may  be  pumped  into  a  sprinkler  or  onto  a  loaded 
manure-spreader  and  applied  to  the  land. 

The  dung  may  be  loaded  directly  into  a  cart  or  manure-spreader  and 
hauled  out  and  spread  on  the  land  as  soon  as  there  is  a  full  load.  The 
objections  to  this  are:  (1)  that  in  winter  in  order  to  keep  the  manure 
from  freezing  it  is  often  necessary  to  carry  it  out  before  a  full  load  has  been 
obtained;  (2)  that  the  land  is  frequently  in  such  condition  that  it  is  im- 
possible to  drive  on  it;  and  (3)  that  the  land  that  is  to  be  fertilized  is  not 
always  ready  for  the  manure.  In  spite  of  these  drawbacks  it  is  becom- 
ing more  generally  the  practice  to  apply  the  manure  directly  to  the  land 
rather  than  to  store  it. 

Manure  is  handled  in  different  ways.  When  the  construction  of  the 
barn  permits  it  the  cart  or  manure-spreader  are  driven  into  the  barn  and 
loaded  from  the  gutters.  Some  barns  are  equipped  with  manure-carriers 
of  which  there  are  two  kinds,  the  rod-track  and  the  rigid-track.  In^each 
an  elongated  tank  usually  of  galvanized  iron  is  suspended  from  an  over- 


132  CITY  MILK  SUPPLY 

head  track  running  immediately  behind  the  cows  and  along  the  edge  of 
the  manure  gutter.  In  the  rod-track  the  carrier  runs  on  a  cable  wire 
which  is  stretched  so  as  to  permit  the  carrier  to  run  by  gravity  from  the 
barn  to  the  dumping  point  where  by  striking  a  trigger  it  is  discharged 
automatically.  Since  this  type  of  carrier  cannot  be  raised  and  lowered, 
much  labor  is  required  in  lifting  the  manure  to  fill  it.  The  end  of  the  rod- 
track  is  attached  to  .a  post  in  such  a  way  that  it  may  be  kept  at  proper 
tension  by  the  use  of  a  turn  buckle  which,  except  when  new,  is  apt  to 
require  frequent  attention  and  so  is  annoying. 

The  rigid-track  carrier  is  more 
expensive  than  the  other  but  is 
more  satisfactory.  An  overhead 
trestlework  supports  a  rigid  iron 
track  on  which,  suspended  below 
on  a  swiveled  iron  frame,  the  car- 
rier runs.  It  is  pushed  along  the 
gutter  as  the  stables  are  cleaned, 
all  high-lifting  of  the  manure  being 
avoided  by  lowering  the  carrier 

FIG.  28,-Manure  carrier.  tiU  {t  little    m°re  than   clears    the 

floor.     When  the  carrier  is  full  it  is 

raised  by  a  gear  arrangement  and  pushed  out  of  the  barn  to  the  dumping 
point  where  it  is  emptied  by  pulling  a  trigger. 

Litter. — The  availability  and  cost  of  bedding  materials  usually  de- 
termines the  choice  as  to  which  shall  be  used ;  other  qualities  to  be  consid- 
rred  are  their  absorptive  power  and  cleanliness.  Doane  of  the  Maryland 
Station  made  a  series  of  tests  to  determine  the  value  of  different  materials 
for  litter,  comparing  them  with  the  material  most  widely  used  by  dairy- 
men for  the  purpose,  whole  wheat  straw,  as  a  standard.  It  was  found 
that  chopped  wheat  straw  is  easily  kicked  about  and  packs  down  closely 
so  that  more  is  required  to  keep  the  cows  clean.  Rye  straw  which  is 
highly  esteemed  for  horse  litter  seemed  poorly  adapted  for  cows  because 
it  is  hard  and  stiff  and  has  low  absorptive  capacity.  Barley  straw  is  not 
used  because  the  beards  irritate  the  animals.  About  one-third  more  by 
weight  was  required  of  corn  stover  but  it  is  not  easily  shoved  about  and 
keeps  the  cows  cleaner.  All  of  these  materials  were  a  little  dusty  but  not 
objectionably  so.  Wet  or  mouldy  straw  is  wholly  unfit  for  bedding.  In 
some  places  weeds  and  fallen  autumn  leaves  are  used  for  bedding;  they 
are  to  be  condemned  for  litter  because  of  the  dust  they  contain.  Sawdust 
stayed  in  place  better  and  kept  the  cows  cleaner  than  any  other  bedding. 
It  was  often  damp  but  this  produced  no  ill  effects.  Sawdust  makes  the 
manure  so  light  that  loss  of  ammonia  may  occur;  it  decays  slowly  and 
tends  to  loosen  up  the  soil  so  that  it  is  possibly  not  the  thing  to  apply  to  a 
light  sandy  soil,  but  on  heavy  ones  it  is  unlikely  to  do  harm  and  may  be 


DAIRY  CATTLE  AND  THE  DAIRY  FARM 


133 


distinctly  beneficial.  It  is  said  that  the  tannic  acid  which  results  from  the 
application  of  large  quantities  of  oak  sawdust  has  sometimes  been  injuri- 
ous to  the  land.  Shavings  have  all  the  good  qualities  of  sawdust  but  being 
light  are  scattered  by  a  strong  breeze.  Both  sawdust  and  shavings  are 
free  from  dust  and  nearly  so  from  mould  and  bacteria;  on  the  whole  they 
probably  make  the  best  litters.  Tables  38  and  39  show  the  absorptive 
powers  Doane  found  different  bedding  materials  to  have,  and  the  amount 
of  them  required  daily. 

TABLE  38. — ABSORPTIVE   POWERS  OF  BEDDING  MATERIALS  (DOANE) 


Material 

Water  absorbed  per 
pound  of  bedding 

Pounds  of  bedding  re- 
quired to  absorb  liquid 
manure  from  one   cow 
for  16  hr. 

Pounds    of    bedding    re- 
quired to  absorb  liquid 
manure  for  24  hr. 

Cut  stover  
Cut  wheat  straw. 
Whole        wheat 
straw 

2.5 

2.0 

2  0 

2.8 

3.3 
3  3 

4.0 
5.0 

5  0 

Sawdust  
Shavings  .  . 

0.8 

2.8 

8.3 
3.0 

12.6 
4.4 

TABLE  39. — AMOUNT  OF  LITTER  REQUIRED  DAILY  PER  Cow  FOR  16  HR.  STABLING1 

Cut  wheat  straw 2.9 

Whole  wheat  straw 2.3 

Cut  corn  stover 3.2 

Sawdust 11.0 

Shavings 2.7 

1  Except  where  bedding  is  regulated  to  absorb  all  the  liquid  manure,  it  is  doubtful 
if  materially  more  bedding  would  be  required  for  24  hr.  stabling. 

Vermin  and  Flies. — The  vermin  that  annoy  most  in  dairy  barns  are 
rats,  mice,  lice,  fleas  and  ticks. 

The  fly  nuisance  is  very  troublesome  to  deal  with.  In  the  United 
States  three  varieties  of  flies,  the  stable  fly,  the  horn  fly  and  the  house  fly 
annoy  cattle.  In  some  States  the  stable  fly  inflicts  severe  losses  but 
though  it  is  conceivable  that  it  might  spread  anthrax  it  is  not  believed 
that  either  it  or  the  horn  fly  spread  diseases  that  commonly  afflict  man 
but  the  house  fly  is  known  to  be  a  disseminator  of  typhoid  fever,  probably 
of  infantile  diarrhea  and  other  intestinal  infections  and  of  tuberculosis. 
The  stable  fly  deposits  its  eggs  in  various  kinds  of  straw,  the  horn  fly  in 
cow  manure  and  the  house  fly  in  horse  manure  and  other  ordure.  As  these 
materials  are  abundant  around  dairy  barns  there  are  bound  to  be  flies. 
It  is  the  common  belief  that  the  falling  off  of  the  milk  flow  in  the  latter 
part  of  summer  is  largely  due  to  the  pestering  of  the  cows  by  flies  but  the 
prime  reasons  for  the  decrease  are  disinclination  of  the  cows  to  eat  and 
shortness  of  pasturage  and  water,  the  flies  being  only  a  minor  contributing 


134  CITY  MILK  SUPPLY 

cause.  At  several  of  the  experiment  stations  the  efficacy  of  various  mix- 
tures that  are  supposed  to  keep  flies  off  the  animals  has  been  tested.  The 
mixtures  are  usually  some  coal-tar  product  combined  with  fish  oil,  resin, 
pine  tar  or  sometimes  with  tobacco.  Several,  if  applied  frequently,  kept 
off  the  flies  but  their  use  did  not  result  in  an  increase,  either  in  milk  flow 
or  butterfat  production. 

The  fly  pest  has  to  be  fought  in  barns,  dairies  and  city  milk  plants 
quite  as  vigorously  as  it  is  fought  elsewhere.  In  the  stable,  although  they 
cannot  bite,  the  flies  annoy  the  animals.  Flies  are  very  fond  of  milk  and 
swarm  into  dairies  and  city  milk  plants  where  they  are  likely  to  infect  it. 
The  best  way  to  keep  down  the  flies  is  to  deprive  them  of  breeding  places. 
This  means  that  manure  bins  should  be  screened  or  in  other  ways  be  made 
flyproof  and  that  the  manure  should  be  carefully  swept  up  from  the 
stables  for  if  it  is  permitted  to  gather  in  small  quantities  on  the  ground 
or  in  crevices  in  the  floor  it  will  surely  yield  its  quota  of  flies.  Also  it  is 
important  to  have  the  manure  removed  at  such  frequent  intervals, 
usually  less  than  10  days,  that  there  will  not  be  time  for  a  generation  of 
flies  to  develop.  The  attempt  has  been  made  to  control  the  breeding  of 
flies  by  mixing  various  substances  with  the  manure.  The  labor  involved 
and  the  cost  have  prevented  the  practice  from  being  generally  adopted. 
The  U.  S.  Department  of  Agriculture  finds  borax  in  the  proportion  of 
0.62  Ib.  to  8  bu.  of  manure  to  be  as  efficacious  as  anything  for  this  pur- 
pose. Garbage  must  be  kept  in  covered  receptacles  and  removed  often. 
Also,  privy  vaults  should  be  built  so  as  to  be  flyproof  and  the  seats 
should  have  covers  that  shut  automatically.  These  measures  should  be 
supplemented  by  effective  screening,  the  use  of  fly  traps  of  the  Hodges 
or  of  the  Minnesota  patterns  and  of  sticky  but  not  of  poison  flypaper 
and  by  swatting  the  fly  that  eludes  these  guards. 

The  Florida  State  Board  of  Health  made  an  interesting  study  of  the 
breeding  of  flies  in  the  floors  of  the  horse  stables  in  Jacksonville.  There 
were  944  stables  having  dirt  floors  and  113,  that  were  typical  of  the  aver- 
age of  such  stables  in  the  city,  were  given  special  study.  The  soil  was 
examined  to  a  depth  of  6  in.  In  94  per  cent,  of  the  stables  where  there 
were  no  chickens  to  eat  them  up,  larva  were  found;  in  the  other  6 
per  cent,  the  soil  had  been  removed  to  a  depth  of  3  or  4  in.  a  few  days 
before  inspection  was  made.  Some  of  the  floors  had  been  swept  clean  of 
manure  and  litter  but  even  in  these,  larvae  were  found  at  a  depth  of  1  to  3 
in.  Soft  wet  ground,  that  which  had  been  wet  by  urine,  was  most 
favorable  to  the  larvse.  In  hard  dry  ground  larvae  were  not  found.  In 
the  city  there  were  136  horse  stables  with  wooden  and  16  with  cement  or 
brick  floors.  Fifty-two  of  these  wood  and  cement  floored  stables  were 
carefully  investigated.  In  none  of  them  were  there  chickens.  In  70  per 
cent,  of  the  floors  larvse  were  breeding  and  in  nearly  one-half  of  these  the 
presence  of  larvae  was  due  to  the  fact  that  there  were  cracks,  broken 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  135 

boards  and  depressions  where  the  broom  did  not  reach;  in  the  remainder 
it  was  due  to  carelessness  on  the  part  of  the  proprietor.  In  23  per  cent, 
of  the  wood  floor  stables  flies  were  breeding  under  the  floors  and  this 
figure  is  low  as  about  one-half  of  the  stables  inspected  were  of  such 
construction  that  flies  might  breed  beneath  the  floors  but  precluded 
determination  of  whether  they  were  doing  so  or  not.  Two  factors  lead 
to  the  breeding  of  flies  under  the  wooden  floors.  First,  in  some  stables 
the  floors  were  not  tight  and  so  permitted  urine  and  particles  of  fly- 
blown manure  to  fall  beneath  the  floor  where  the  warmth  and  moisture 
were  favorable  to  larval  development.  Second,  in  stables  of  this  sort 
having  loose  foundations  flies  will  oviposit  in  suitable  material  that  they 
find  beneath  the  barns. 

Larvae  were  found  in  many  manure  heaps  but  often  the  manure  had 
been  hauled  away  a  short  while  before  inspection  so  that  in  this  particular 
the  percentage  of  positive  findings,  38  per  cent,  of  all  the  stables,  was 
low. 

Mosquitos. — Mosquitos,  like  flies,  greatly  annoy  cattle  and  the  writer 
has  seen  invasions  of  dairy  districts  by  certain  varieties  of  salt  marsh 
mosquitos  that  were  really  disturbing  but  speaking  broadly  it  is  unusual 
for  mosquitos  to  trouble  herds  greatly.  To  the  farmers  themselves 
they  may  do  serious  injury  for  anopheles  mosquitos,  infected  with  malaria 
transmit  the  disease  to  man  causing  him  to  be  sickly  and  listless,  conse- 
quently his  business  suffers.  To  avoid  such  misfortune  and  to  prevent 
the  family  from  being  pestered  by  the  ordinary  house  mosquito,  culex, 
rain  barrels  and  cisterns  should  be  kept  tightly  covered  that  mosquitos 
cannot  enter  them  to  lay  their  eggs.  There  should  be  good  drainage 
about  the  house  and  barn,  for  in  puddles  that  are  permanent  enough  to 
last  10  days  the  insects  will  mature.  Pools  around  manure  heaps,  cess- 
pools and  the  water  that  accumulates  in  privy  vaults,  also  make  prolific 
breeding  places.  Sagging  gutters  likewise  furnish  their  quota  of  mos- 
quitos. Places  that  cannot  be  drained  can  be  rendered  unfit  for  breeding 
by  spraying  them  with  oil. 

Milk  Houses. — Besides  barns,  milk  houses  are  required  on  dairy  farms 
and  ice  houses  are  so  useful  as  to  be  almost  a  necessity. 

Milk  or  dairy  houses  vary  a  great  deal  in  type  because  they  must 
be  suited  to  the  character  of  the  dairyman's  business;  when  the  milk  is 
shipped  in  bulk  a  very  simple  structure  suffices  but  where  a  producer  car- 
ries on  a  retail  business  a  more  elaborate  building  is  required.  The  pur- 
pose of  a  milk  house  is  to  afford  a  place  to  which  the  milk  may  be  carried 
as  soon  as  it  is  drawn  from  the  cow  and  in  which  it  may  be  cooled,  made 
ready  for  shipment  or  delivery,  and  be  stored.  Milk  houses  are  some- 
times in  the  dairyman's  dwelling  or  occasionally  in  one  end  of  his  ice  house, 
more  often  in  or  attached  to  the  barn  but  are  usually  in  a  separate  build- 
ing a  short  distance  from  the  barn.  Of  these  situations  the  least  favorable 


136 


CITY  MILK  SUPPLY 


is  the  first  because  it  is  practically  impossible  to  keep  the  business  of  the 
household  separate  from  that  of  the  dairy.  Members  of  the  family, 
especially  the  children,  run  in  and  out  of  the  milk  room;  things  that  should 
be  kept  in  the  kitchen  find  their  way  into  the  dairy  room;  there,  clothes  that 
should  be  hung  in  a  closet  or  in  the  shed  find  a  convenient  hook;  the  milk- 
room  doors  are  left  ajar;  odors  from  the  kitchen  often  permeate  the  milk 
room  and  other  petty  things  interfere  with  the  routine  of  well-ordered  dairy 
business.  Most  objectionable,  are  those  dairy  rooms  that  are  located 
in  the  cellars  of  houses,  for  they  are  likely  to  be  dark,  damp  and  poorly 


FIG.  29. — Inexpensive  dairy  house  for  farmer  handling  milk  in  bulk.     (40th  Annual 
Report,  Boston  Health  Department.) 

ventilated  besides  which  dirt  is  apt  to  sift  down  from  the  floors  above 
and  be  blown  in  from  the  ground.  Another  objection  to  having  the 
milk  room  in  the  house  is  that  in  case  infectious  disease  appears  in  the 
household  such  a  location  is  most  unfortunate. 

The  location  of  the  milk  room  in  or  attached  to  the  barn  is  usually 
unsatisfactory  chiefly  because  of  the  difficulty  of  keeping  out  odors,  but 
also  because  it  is  hard  to  keep  the  room  scrupulously  clean,  to  prevent 
it  from  being  overrun  by  the  help  and  to  keep  out  flies,  rats  and  other 
vermin.  However,  some  dairymen  do  overcome  these  difficulties  and 
maintain  thoroughly  satisfactory  milk  rooms  within  their  barns. 

Altogether  the  best  location  for  the  dairy  house  is  detached  from  the 
barn  and  150  to  200  ft.  from  it  and,  if  possible,  near  the  dwelling.  The 
object  of  the  milk  house  is  to  have  a  place  where  the  milk  can  be  weighed, 
tested  clarified,  separated,  cooled,  put  in  its  final  container  and  stored 
in  surroundings  free  from  odor,  dust  and  confusion.  Also  it  is  the  in- 
tention to  provide  a  place  where  th°  workman  may  attend  to  these  things 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  137 

free  from  the  interruption  of  outsiders.  It  is  obvious  that  the  purpose 
is  most  likely  to  be  attained  in  a  building  devoted  solely  to  the  handling 
of  milk  and  especially  designed  therefor. 

The  dairy  house  should  be  placed  so  as  to  save  the  milkers  as  many 
steps  as  possible  in  going  to  and  from  the  milk  house  with  the  milk. 
Usually  this  puts  the  building  about  midway  of  the  length  of  the  barn.  On 
some  farms  the  milkers  instead  of  carrying  the  milk  from  each  cow  to  the 
milk  house  to  weigh,  sample  and  record  it,  take  it  for  this  purpose  to  a  small 
room  within  the  barn  and  then  dump  it  into  a  funnel  connected  by  a  line 
of  seamless  "sanitary"  piping  with  the  milk  house  into  which  it  flows 
by  gravity  through  the  pipe.  Such  an  arrangement  is  convenient  and 
labor-saving  but  its  success  depends  almost  wholly  on  the  care  that  is 
taken  to  keep  the  pipe  clean  and  sterile.  In  dairies  where  the  milk  of 
the  individual  cows  is  not  weighed  the  milkers  often  pour  the  milk  into 
a  large  can,  which  when  full  is  carried  into  the  milk  house.  This  can 
should  not  be  set  in  the  stable  proper  for  rilling  but  without  in  an  adjoin- 
ing room  or  some  other  convenient  place  where  it  will  be  protected  from 
the  odors  of  the  animals,  from  dust,  flies  and  the  attention  of  cats. 

In  addition  to  being  located  conveniently  to  the  barn,  the  milk 
house  should  be  situated  where  it  will  have  good  drainage  both  for  its 
own  wastes  and  for  the  surface  and  ground  water  without,  where  it  will 
be  free  from  dust  and  odor  and  where  an  abundant  supply  of  pure  water 
is  accessible.  In  a  country  of  uneven  topography  it  is  usually  not  diffi- 
cult to  secure  good  drainage  but  on  the  prairies  it  often  is  so  and  consider- 
able labor  is  required  to  make  the  house  and  the  land  immediately  around 
it  dry.  If  the  dairy  house  is  on  bare  ground  it  will  be  dusty,  consequently 
the  labor  of  keeping  the  milk  and  utensils  clean  will  be  greatly  increased. 
The  ground  around  the  dairy  house  should  be  turfed.  The  driveway  to 
the  store-room  should  be  run  so  as  not  to  pass  beneath  the  windows  of 
the  milk  room  and  should  be  oiled  or  paved  if  it  is  prone  to  get  dusty. 
Dust  raised  by  automobiles  and  wagons  will  be  troublesome  if  the  dairy 
house  is  not  located  a  considerable  distance  from  the  highway.  Odors  are 
usually  easily  avoided  if  care  is  taken  not  to  put  the  milk  house  where  it 
gets  them  from  the  kitchen,  hen  houses,  hog  pens,  latrines  or  manure  piles. 
Proximity  to  the  last  three  of  these  is  particularly  objectionable  for  in  ad- 
dition to  being  a  source  of  evil  odors  they  attract  or  breed  flies,  making  it 
exceedingly  difficult  to  keep  the  dairy  house  free  from  these  filthy  insects. 

An  abundant  supply  of  water  in  the  dairy  house  is  essential  to  clean- 
liness and  running  water  is  all  but  indispensable,  for  a  dairyman  can  ill 
afford  to  spend  his  time  toting  water.  Where  there  is  a  public  water 
supply  it  often  can  be  piped  to  the  dairy  house;  where  there  is  none 
water  may  be  pumped  by  a  windmill,  hydraulic  ram,  or  gasolene  engine 
to  a  reservoir  or  tank  whence  it  will  flow  by  gravity  to  the  dairy  house. 

Dairy  'houses  are  usually  built  in  an  inexpensive  way;  so  in  their 


138  CITY  MILK  SUPPLY 

construction,  wood  is  commonly  used  but  they  may  be  of  brick,  ce- 
ment or  masonry.  Small  dairies  having  but  few  cows  and  delivering 
milk  in  bulk  often  have  wood  frame  milk  houses  of  but  a  single  room 
with  wooden  floors  and  tanks.  They,  and  all  other  dairy  houses,  should 
be  well-lighted,  well-ventilated  and  should  be  completely  screened  to 
keep  out  flies  and  other  insects.  They  should  have  well-fitting  doors 
that  should  be  kept  closed  in  order  to  keep  out  cats,  hens  and  rats  whose 
droppings  make  sanitary  milk  production  impossible.  Within,  the  houses 
should  have  shelves  whereon  the  cans  and  other  utensils  can  be  kept 
inverted  and  without,  there  should  be  a  sunning  rack  for  airing  the  tin- 
ware. If  cans  of  milk  are  cooled  with  water  in  tanks  it  should  stand  well 
above  the  level  of  the  milk  in  the  can  and  the  milk  should  be  mixed  with 
a  clean  stirrer  till  brought  to  near  the  desired  temperature  when  the  covers 
should  be  put  on  the  cans.  Water  in  the  tanks  should  be  kept  clean  and 
covers  for  the  tanks  are  recommended.  Warm  milk  should  not  be  mixed 
with  cold  milk  nor  new  milk  with  old.  Milk  is  often  injured  by  the  use 
of  unclean  or  sour  cloths  to  wipe  the  cans  or  other  utensils.  These 
towels  should  either  be  washed  carefully  and  dried  quickly  in  the  sun, 
or  else  should  be  of  such  cheap  material  that  they  can  be  thrown  away 
after  being  once  used. 

For  dairies  having  25  cows  a  10  by  20-ft.  three-room  milk  house  is 
suitable.  The  floor  should  be  of  concrete  and  should  be  rounded  at  the 
walls  and  corners  to  facilitate  cleaning  and  should  be  sloped  gently  to  a 
drain  in  the  middle.  The  walls  should  be  of  cement  plaster  on  metal 
lathing  to  the  windows,  above  which  they  may  be  of  plaster  or  of  matched 
stuff  painted  white — preferably  with  waterproof  enamel.  The  windows 
should  be  flush  with  the  walls.  The  boiler  room,  containing  the  boiler, 
coal  bins  and  workbench  is  placed  as  far  as  possible  from  the  milk-han- 
dling room  in  order  to  protect  it  from  coal  dust  and  ashes.  There  should 
be  two  doors  to  the  boiler  room,  one  opening  outside  and  the  other  to  the 
washroom. 

The  washroom  should  be  supplied  with  hot  and  cold  water  and  should 
be  equipped  with  a  sink,  bottle  washer,  bottle  rack  and  can  racks.  There 
must  be  apparatus  for  sterilizing  utensils.  For  small  farms  Ayres's  device 
which  is  described  in  Farmers'  Bulletin  No.  748  of  the  U.  S.  Department 
of  Agriculture  will  suffice  but  on  the  larger  dairy  farms  sterilizing  appa- 
ratus such  as  is  used  for  bottles  and  cans  in  city  milk  plants,  is  needed. 
The  bottle  cases  should  be  kept  in  this  room.  Besides  the  door  to  the 
boiler  room  there  should  be  one  opening  outside  and  one  to  the  milk- 
handling  room;  the  milk-handling  room  should  contain  the  cooler,  sepa- 
rator, concrete  storage  tanks  and  ice  chest  if  there  is  one. 

If  milk  is  bottled  or  butter  is  made  at  the  dairy  a  16  by  30-ft.  four- 
room  dairy  house  is  required.  At  one  end  should  be  placed  the  receiving 
room  where  milk  is  weighed  and  tested.  It  is  then  put  through  a 


DAIRY  CATTLE  AND  THE  DAIRY  FARM  139 

clarifier  or  poured  directly  in  a  funnel  and  run  by  gravity  in  a  pipe  through 
the  wall  over  the  cooler  in  the  bottling  room.  This  room  contains  the 
bottling  machine,  the  capping  machine,  the  separator  and  ice  box.  The 
pressure  sterilizer  which  is  located  in  the  washroom  at  one  end  opens  into 
the  bottling  room  which  is  convenient,  for  it  makes  it  possible  to  get  the 
bottles  and  other  necessary  utensils  into  the  milk  room  without  exposing 
them  to  dust  and  unnecessary  handling.  The  bottling  room  is  connected 
by  a  door  to  the  washroom  and  that  in  like  manner  to  the  boiler  room. 
These  two  rooms  are  located  at  one  end  of  the  building  and  contain  the 
usual  conveniences,  apparatus  and  supplies. 

There  must  be  hot  water  in  the  milk  house  and  getting  it  is  often 
something  of  a  problem  to  dairymen  of  limited  means.  The  least  satis- 
factory way  of  heating  water  is  to  do  it  in  a  tin  boiler  on  a  stove;  but  little 
better  is  that  of  heating  it  in  a  bricked-up  iron  kettle;  more  convenient  is 
a  galvanized-iron  tank  placed  over  a  large  kerosene  burner.  When  gas 
is  available  instantaneous  gas  heaters  give  satisfaction,  but  a  1  to,2-hp. 
steam  boiler  is  best  of  all  for  by  turning  the  steam  into  the  wash  tank 
hot  water  is  quickly  obtained  and  moreover  the  steam  is  available  for 
sterilizing  bottles  and  utensils,  for  driving  the  clarifier  and  separator  and 
for  heating  skim-milk  for  calves.  The  first  cost  of  a  steam  boiler  is  con- 
siderable but  in  the  end  it  is  cheapest  and  best.  It  is  unsafe  to  have 
heating  appliances  in  milk  rooms  that  are  in  barns. 

Ice  Houses. — Since  by  the  use  of  well  or  spring  water  milk  can  seldom 
be  cooled  to  50°F.  whereas  it  can  be  cooled  to  40°F.  in  tanks  containing 
water  and  floating  ice,  it  is  highly  desirable  for  a  farmer  to  have  ice  on  the 
premises  in  order  that  he  may  keep  his  milk  in  prime  condition.  Where 
climatic  conditions  permit  it  farmers  harvest  their  own  ice.  The  U.  S. 
Department  of  Agriculture  estimates  that  where  whole  milk  is  sold,  in 
the  Northern  States  1.5  tons,  and  in  the  Southern  2  tons,  of  ice  a  year  are 
required  to  cool  the  milk  of  one  cow.  Only  about  1,000  Ibs.  of  ice  per  cow 
are  required  where  the  farmer  is  delivering  cream  three  times  a  week. 
Of  course  these  estimates  assume  properly  constructed  ice  houses  details 
for  which  are  issued  by  the  Federal  Government  and  several  State  boards. 

Sources 

MERRITT,  "The  Production  and  Consumption  of  Dairy  Products,"  Bull.  177,  U.  S. 

Dept.  Ag. 
MORSE,  "The  Ancestry  of  Domesticated  Cattle,"  reprint  27th  Annual  Report  Bureau 

Animal  Industry,  U.  S.  Dept.  Ag.,  1910. 
PLUMB,  "Types  and  Breeds  of  Farm  Animals,"  1906. 
ECKLES,  "Dairy  Cattle  and  Milk  Production,"  1914. 
LANE,  "The  Business  of  Dairying,"  1914. 

HUNZIKER,  "Milk  Production,"  III,  Circ.  20,  Purdue  Ag.  Expt.  Sta.,  1909. 
ALVORD,  "Breeds  of  Dairy  Cattle,"  Farmer's  Bull.  106,  U.  S.  Dept.  Ag.,  1898. 
GRAND  ALL,  "A  Dairy  Cow  Score  Card  and  Its  Use,"  Hoard's  Dairyman,  vol.  50,  No. 

15,  p.  448,  1915. 


140  CITY  MILK  SUPPLY 

ALLEN,  "American  Cattle,"  1887. 

GRAVES,   "An  Experiment  with  Milk  Veins,"  Hoard's  Diaryman,  vol.  52,  No.  20, 

1916. 
HAYDEN,  "Official  Records  of  Purebred  Dairy  Cows,"  Univ.  111.  Expt.  Sta.,  Bull. 

160,  July,  1912. 
HAECKER  and  FRANSDEN,  "Results  of  the  Douglas  County  Cow-testing  Association," 

Univ.  Neb.  Ag.  Expt.  Sta.,  Bull.  129,  May,  1912. 
REED,  "The  Dickinson  County  Cow-testing  Association,  Kan.  Ag.  Expt.  Sta.,  Circ.  35, 

1914. 
CARROLL,  "Report  of  the  Richmond-Lewiston  Cow-testing  Association,"  Utah  Ag. 

College  Expt.  Sta.,  Bull.  127,  August,  1913. 
BARNES,  "Comparison  and   Improvement   of  Dairy   Herds   in    Tennessee,"    Univ. 

Tenn.  Ag.  Expt.  Sta.,  Bull.  83,  March,  1909. 
SAUNDERS  and  HOLDAWAY,  "Cooperative  Herd  Testing,"  V.  P.  I.  Ag.  Expt.  Sta., 

Bull.  190,  January,  1911. 

RASMUSSEN,  "Cost  of  Milk  Production,"  N.  H.  State  College  and  Expt.  Sta.  Exten- 
sion Bull.  2,  June,  1913. 
BLISS,   BUSH  and  LINCH,   "Cooperative  Cow-testing  Associations  in  Iowa,"  Iowa 

State  College  Expt.  Sta.,  Extension  Bull.  7,  April,  1911. 

ANDERSON,  "The  Year's  Work  of  the  Ferndale  (Humboldt  Co.)  Cow-testing  Asso- 
ciation," Univ.  Cal.  Ag.  Expt.  Sta.,  Bull.  233. 
ERASER,  "Cow  Index  of  Keep  and  Profit,"  Univ.  111.  Ag.  Expt.  Sta.,  Circ.  134,  2d  Ed., 

April,  1913. 
ERASER,   "Economic   Milk  Production,"   1st  Annual   Report  of  the  International 

Association  of  Dairy  and  Milk  Inspectors,  pp.  95-101,  1912. 
GAINES,  "Cow-testing  Association  Work  in  Illinois,"  Hoard's  Dairyman,  20,  June, 

1913. 

FRASER,  "Conservation  of  Energy,"  Circ.  134,  Univ.  111.  Ag.  Expt.  Sta.,  April,  1910 
FRASER,  "Economy  of  the  Round  Dairy  Barn,"  Bull.  143,  Univ.  111.  Ag.  Expt.  Sta., 

February,  1910. 
PARKER,  "Pathological  Dangers  to  Domestic  Animals  from  Contaminated  Streams," 

Am.  Jour.  Public  Health,  vol.  3,  No.  1,  pp.  67-71,  January,  1913. 
BITTING,  "The  Relation  of  Water  Supply  to  Animal  Diseases,"  Purdue  Univ.  Ag. 

Expt.  Sta.,  Bull.  70,  1898. 
EKBLAW,  "Barn  Structures,"  pp.  235-252. 
NICHOLLS,   "Construction  and  Equipment  of  Dairy  Barns,"   Bull.    179,   Ky.   Ag. 

Expt.  Sta. 
COOK,  "Construction  of  Sanitary  Dairy  Stables,"  Cornell  Reading  Course  for  Farmers, 

series  5,  No.  23,  January,  1905. 
BUCKLEY  and  LAMSON,  "Open  Stables  vs.  Closed  Stables  for  Dairy  Animals.     The 

Bacterial  Content  of  Milk  Produced  in  the  Open  Stable  and  in  the  Closed  Stable," 

Bull.  177,  Md.  Ag.  Expt.  Sta.,  May,  1913. 
ANDERSON,  "The  Dairy  Cows  Record  and  the  Stable,"  Univ.  Cal.  Ag.  Expt.  Sta., 

Bull.  204. 

NOURSE,  "Barns,"  Va.  Ag.  Expt.  Sta.,  Bull.  106,  1899. 
DOANE,  "Tests  of  Materials  for  Bedding  Cows,"  Bull.  104,  Md.  Ag.  Expt.  Sta.,  July, 

1905. 

KING,  "Ventilation,"  1908. 
REYNOLDS  and  LIPP,  "Stable  Ventilation,  Purpose,  Scope  and  Need  of  Such  Work," 

Bull.  98,  Univ.  Minn.  Ag.  Expt.  Sta.,  1906. 
WINSLOW,  PHELPS  ET  AL.,  "Some  Results  of  the  First  Years  Work  of  the  New  York 

State  Commission  on  Ventilation,"  Am.  Jour.  Public  Health,  vol.  5,  No.  2.  pp. 

88-118,  1915. 


DAIRY  CATTLE  AND  THE  DARIY  FARM  141 

GRISDALE  and  ARCHIBALD,  "Ventilation  of  Farm  Buildings,"  Bull.  78,  Dominion  of 

Canada,  Dept.  Ag.,  Dominion  Experimental  Farms,  May,  1914. 
GRISDALE,  "Milk  Production  in  Canada,"  Bull.  72,  Dominion  of  Canada  Dept.  Ag., 

Dominion  Experimental  Farms. 
ARCHIBALD,  "The  Modern  Dairy  Barn,"  7th  American  Convention  International  Milk 

Dealer's  Association,  pp.  21-31,  October,  1914. 
RILEY  AND  HOWARD,  "The  Horn  Fly,"  Sp.  Bull,  U.  S.  Dept.  Ag. 
BISHOPP,  "The  Stable  Fly,"  Farmer's  Bull.  540,  U.  S.  Dept.  Ag.,  1913. 
HOWARD,  "House  Flies,"  Farmer's  Bull.  459,  U.  S.  Dept.  Ag.,  1911. 
HOWARD,  "Experiments  in  the  Destruction  of  Fly  Larvae  in  Horse  Manure,"  Bull. 

118,  U.  S.  Dept.  Ag.,  1914. 
WASHBURN,  "The  Minnesota  Fly  Trap,"  Circ.  24,  State  Entomologist  of  Minnesota, 

1912. 
FERRY,   "Sanitary  Reforms  in  Jacksonville,"  Florida  Health  Notes,  vol.  7,  No.  4, 

April,  1912,  published  by  the  State  Board  of  Health. 
KELLY  and  PARKS,  "A  Plan  for  a  Small  Dairy  House,"  Circ.  195,  U.  S.  Dept.  Ag., 

1912. 
Hoard's  Dairyman,  vol.  47,  No.  20,  "The  Milk  House,"  p.  717;  "The  Farm  Milk 

House,"  p.  719,  June  12,  1914. 

KELLY,  "A  Milk  House,"  Hoard's  Dairyman,  vol.  19,  No.  14,  p.  54,  April  30,  1915. 
AYRES,  "A  Simple  Steam  Sterilizer  for  Dairy  Farm  Utensils,"  Farmer's  Bull.  748, 

U.  S.  Dept.  Ag.  July  22,  1916. 

PICKELS,  "Farm  Ice  Houses,"  Circ.  30,  Mass.  State  Board  Ag.,  June,  1914. 
BOWEN  and  LAMBERT,  "Ice  Houses  and  the  Use  of  Ice  on  the  Dairy  Farm,"  Farmer's 

Bull.  623,  U.  S.  Dept.  Ag.,  January,  1915. 


CHAPTER  IV 
SANITARY  MILK  PRODUCTION 

Milk  Must  Satisfy  the  Purchaser. — To  bring  good  price,  milk  must 
have  good  food  value  and  certain  other  qualities  that  are  affected  by  the 
sanitary  conditions  under  which  it  is  produced.  Care  must  be  taken  to 
keep  milk  clean. 

Dirty  Milk. — The  dirt  that  gets  into  milk  is  of  many  sorts  and  comes 
from  different  sources.  The  large  particles  are  noticed  and  objected  to 
by  consumers  but  the  invisible  dirt  that  comes  from  a  foul  strainer  cloth 
or  from  the  film  of  milk  that  dries  on  the  carelessly  washed  pail  escapes 
attention,  yet  it  is  quite  as  likely  to  deterioriate  the  milk.  Dirt  from 
various  sources  is  not  equally  objectionable.  That  blown  from  a  newly 
ploughed  field  is  regarded  with  less  aversion  than  that  blown  from  a 
much-used  driveway  because  the  one  is  relatively  free  from  animal  ex- 
cretions whereas  the  other  is  likely  to  contain  them.  The  dirt  or  dust 
raised  in  a  barn  by  tumbling  hay  from  the  mows  is  of  a  different  sort 
than  that  raised  by  currying  the  cows.  The  dirt  from  utensils,  from  soil, 
from  dung,  from  the  skin  of  animals  and  from  other  sources  each  has  its 
peculiar  character  and  may  be  expected  to  affect  milk  differently.  Wherein 
does  this  difference  chiefly  lie?  Not  in  the  dirt  itself,  but  in  the  bacteria 
attached  to  it.  Practically  all  dirt  that  gets  into  milk  carries  its  quota 
of  bacteria  but  some  of  it  is  much  more  heavily  seeded  with  germs  and 
dirt  from  some  sources  is  more  likely  than  that  from  others  to  carry 
those  germs  that  markedly  affect  milk,  or  those  that  infect  people  who 
drink  it.  So  all  dirt  and  all  sources  of  pollution  are  not  of  equal  im- 
portance. Bacteria  are  washed  into  milk  from  the  dirt  that  falls  into 
it  and  much  dirt,  as  for  instance  manure,  partially  dissolves;  consequently 
the  removal  of  visible  particles  by  straining  or  centrif ugalizing  does  not  re- 
store milk  to  its  original  purity,  for  these  operations  leave  bacteria  in  the 
milk.  To  keep  dirt  out  of  milk  is  comparatively  easy  but  once  it  is  in, 
to  remove  it  completely  is  impossible.  Milk  once  contaminated  remains 
so.  Therefore,  cleanliness  at  the  farm  is  of  the  utmost  importance,  for 
if  it  is  rieglected  there  all  the  pains  that  are  taken  with  the  milk  afterward 
are  in  part  nullified.  Since  clean  milk  ordinarily  contains  but  few  bac- 
teria, and  milk  that  has  been  much  exposed  to  dirt  contains  many,  low 
bacterial  counts  of  milk  at  the  farm  have  been  widely  accepted  in 
the  United  States  as  a  guarantee  of  the  use  of  cleanly  methods  by  the 
dairyman.- 

142 


SANITARY  MILK  PRODUCTION  143 

Bacteria  decompose  milk;  sterile  milk  will  keep  indefinitely,  but  milk 
that  contains  many  bacteria  rapidly  disintegrates  at  ordinary  tempera- 
tures. Normally,  clean  milk  has  a  pleasant  flavor  and  odor  but  dirty 
milk  is  apt  to  be  disagreeable  either  from  dung  which  imparts  a  "cowy" 
taste  or  from  products  of  bacterial  decomposition  which  are  often  dis- 
gusting to  the  palate  and  foul-smelling.  Dirty  milk  is  frequently  unsuited 
to  manufacturing  of  dairy  products  because  of  the  bacteria  that  it  contains. 
While  clean  milk  cannot  be  said  to  be  safe  milk  in  the  sense  that  it  is 
necessarily  free  from  disease  germs,  it  is  probably  true  that  the  cleanly 
dairyman  takes  more  pains  to  protect  his  milk,  so  far  as  he  can,  from  in- 
fection than  the  dirty  one  does.  In  the  words  of  the  late  G.  M.  Whitaker 
"  dirty  milk  ought  not  to  be  considered  a  merchantable  article  at  any 
price  no  matter  how  low." 

The  householder  objects  to  dirty  milk  for  several  reasons.  In  the 
first  place,  dirt  in  the  milk  bottle  serves  warning  that  a  food  product 
which  is  in  constant  use  in  the  home  is  being  handled  carelessly.  In  the 
second,  dirt  is  offensive  to  the  senses;  milk  that  looks  dirty,  that  smells 
bad  or  that  is  off  flavor,  is  not  relished.  In  the  third,  there  is  a  firmly 
gounded  conviction  among  most  people  that  decency  demands  scrupulous 
cleanliness  in  the  handling  and  preparation  of  food  and  this  feeling  is 
outraged  by  the  presence  of  dirt  in  milk.  Finally,  the  belief  is  enter- 
tained that  dirty  milk  causes  intestinal  disturbances  in  children,  particu- 
larly among  those  under  2  years  of  age,  and  many  adults  fearing  the  effect 
of  such  milk  on  their  own  health,  forego  its  use. 

Milk  of  Extra  Quality  More  Expensive  to  Produce. — Large  city  milk 
dealers  and  manufacturers  of  dairy  products  pass  on  the  milk  their  patrons 
bring  them  and  often  establish  a  scale  of  prices  based  on  fat  content, 
cleanliness,  bacterial  count  or  other  considerations,  but  citizens  in  general 
have  delegated  to  boards  of  health  the  duty  of  judging  the  quality  of 
milk  and  of  determining  the  safeguards  that  shall  surround  its  production. 
So,  to  many  dairyman  the  production  of  sanitary  milk  means  little  more 
than  working  under  conditions  imposed  by  these  boards.  While  such  a 
view  is  natural  it  is  not  the  most  helpful  one.  Sanitation  as  applied  to 
dairying  should  be  regarded  first,  as  safeguarding  the  business  with  pre- 
cautions that  reduce  the  losses  of  producer  and  consumer  from  disease 
and  second,  as  tending  to  secure  successful  marketing.  The  attainment 
of  these  objects  costs  money  so  that  the  dairyman  is  limited  in  his  efforts 
to  secure  them  by  the  willingness  of  his  customers  to  pay  enough  for  safe 
and  superior  milk  to  warrant  its  production.  Most  farm  products  give 
visible  evidence  of  their  quality  so  that  the  public  is  willing  and  expects 
to  pay  high  prices  for  extra-fine  meats,  grains,  fruits  and  flowers  and  they 
are  graded  in  the  market  as  firsts,  seconds,  etc.  With  milk  and  to  some 
extent  with  its  products  this  is  not  the  case.  It  may  be  possible  for  the 
discriminating  buyer  to  tell  the  best  from  the  poorest,  but  to  distinguish 


144 


CITY  MILK  SUPPLY 


between  intermediate  grades  is  impossible;  so  consumers  are  prone  to 
think  that  all  milk  is  the  same  and  to  be  loth  to  pay  more  for  one  dairy- 
man's than  for  another's. 

So,  while  those  who  have  the  best  interests  of  dairying  at  heart  fully 
realize  that  milk  should  be  produced  in  a  sanitary  way,  they  are  keenly 
alive  to  the  fact  that  the  cost  of  doing  so  must  be  kept  at  minimum. 
They  are  compelled  to  demand  that  the  protective  regulations  imposed 
on  the  industry  by  those  who  are  chiefly  interested  in  having  the  consumer 
supplied  with  wholesome  uninfected  milk  shall  be  such  as  really  accom- 
plish this  purpose,  and  that  they  shall  not  be  of  such  a  character  as  to  add 
materially  to  the  expense  of  producing  and  marketing  milk,  without 
actually  furnishing  an  equivalent  of  additional  protection.  Rational 
dairy  sanitation  is  not  to  be  secured  by  adopting  preventive  measures 
against  every  conceivable  source  of  pollution,  but  by  first  determining 
the  sources  of  contamination  and  infection,  and  then  proceeding  to  elimi- 
nate the  important  ones. 

Sources  of  Contamination. — Observation  and  experiment  point  out 
many  sources  of  contamination.  As  yet  opinion  as  to  their  relative  im- 
portance is  formed  on  common  sense  and  on  the  studies  of  competent  men 
whose  experiments  have  of  necessity  been  conducted  in  a  somewhat 
desultory  manner.  More  comprehensive  work  is  under  way  and  no  doubt 
will  be  helpful  in  confirming  some  of  our  opinions  and  in  modifying  others. 


The  sources  of  contamination  are: 


1.  The  cow 


2.  Immediate  environment. 


3.  Man 


Buccal,  aural  and 
nasal  discharges. 
Anal  and  urinary 

discharges. 
Skin. 
Clothes. 
4.  Domestic  animals,  vermin  and  flies. 


The  udder. 

Fecal  and  urinary  discharges. 
Buccal  and  nasal  discharges. 

Matter  from  the  coat — Hair,  skin,  plants,  barn- 
yard. 

Air,  ceiling,  ledges,  floor,  etc. 
Feed 

Mouldy     hay,     muddy     hay,     smutty 

straw,  horse  manure  and  sand. 
Bedding  {  vs. 

Shavings,    corn   stalks,    sawdust,   peat, 

moss,  cocoa  shells. 

[  Pails,    strainers,    separators,     clarifiers 
|      coolers,  piping,  bottles,  cloths. 
[  Water  and  ice. 


Utensils 


SANITARY  MILK  PRODUCTION  145 

Bacteria  Derived  from  the  Udder. — Lister,  according  to  Harding  and 
Wilson,  made  the  first  observations  on  the  bacterial  content  of  milk  from 
the  udder  and  upon  the  results  of  his  determinations  on  two  small  samples, 
came  the  belief  that  milk  within  the  healthy  udder  is  germ-free.  Work 
by  Lehmann  and  his  pupil  Schulz,  in  1890,  showed  that  fore-milk  con- 
tained many  bacteria,  middle-milk  fewer  and  the  stoppings  still  less.  In 
this  country  Moore  confirmed  these  results.  He  and  his  pupil  Ward  made 
examinations  of  excised  tissue  from  different  parts  of  functioning  udders 
of  freshly  slaughtered  milch  cows  and  were  able  to  demonstrate  bacteria 
in  the  finer  ramifications  of  the  milk  canal  as  well  as  in  other  parts  of  the 
udder.  At  another  time  they  showed  that  the  organisms  which  gave  rise 
to  gas  and  taint  in  a  cheese  curd  originated  in  the  udder.  The  bacteria 
work  their  way  from  the  outside,  up  the  teat  canal  into  the  milk  cistern 
and  thence  into  the  milk  canals.  It  is  also  possible  but  unusual  for 
bacteria  to  find  their  way  into  the  milk  within  the  udder  from  the  blood 
of  the  cow. 

Bergey  of  the  University  of  Pennsylvania,  in  the  summer  of  1903, 
studied  the  number  and  nature  of  bacteria  in  milk  as  it  comes  from  the 
udder.  Two  hundred  and  seventy-two  samples  were  examined  and  the 
bacteria  found  varied  from  0  to  93,100  per  cubic  centimeter.  Of  the 
entire  number  of  samples  collected  directly  from  the  udder  87,  or  32  per 
cent.,  contained  no  bacteria;  118,  or  43.64  per  cent.,  contained  less  than 
500  bacteria  per  cubic  centimeter  and  28,  or  10.29  per  cent.,  contained 
over  5,000  bacteria  per  cubic  centimeter. 

He  also  examined  the  milk  from  each  of  the  four  quarters  of  20  cows 
and  obtained  results  such  as  those  in  Table  40. 


TABLE  40. — BACTERIAL  CONTENT  OF  MILK  FROM  FOUR  QUARTERS  OF  Cows  (BERGEY) 

Cow                          Quarter  of  the  udder  Bacteria  per  cubic  centi- 
meter 

9                        Right  fore  75 

Left  fore  0 

Right  hind  0 

Left  hind  0 

6                       Right  fore  75 

Left  fore  25 

Right  hind  150 

Left  hind  25 

Right  fore  3,400 

14                       Left  fore  7,425 

Right  hind  4,200 

Left  hind  1,900 
10 


146 


CITY  MILK  SUPPLY 


TABLE  40. — BACTERIAL  CONTENT  OF  MILK  FROM  FOUR  QUARTERS  OF  Cows  (BERGEY) 

— (Continued) 


Cow 


19 


20 


Quarter  of  the  udder 

Right  fore 
Left  fore 
Right  hind 
Left  hind 

Right  fore 
Left  fore 
Right  hind 
Left  hind 

Right  fore 
Left  fore 
Right  hind 
Left  hind 


Bacteria  per  cubic  centi- 
i  meter 

14,100 

8,400 
3,150 
1,850 

16,300 

575 

1,250 

53,450 

250 

850 

175 

44,300 


The  common  occurrence  of  streptococci  in  milk  attracted  Bergey's 
attention  and  he  pointed  out  that  in  many  instances  there  was  present  in 
one  or  more  quarters  of  the  udder  some  evidence  that  the  cow  had  suffered 
from  mammitis.  In  other  cases  the  udder  was  uninjured  and  there  was 
no  history  of  the  disease,  but  he  suggested  that  the  attack  may  have  been 
so  mild  as  to  escape  notice,  or  that  it  may  have  occurred  so  long  ago  as  to 
have  been  forgotten. 

On  account  of  the  danger  to  be  apprehended  from  contagious  mammi- 
tis, the  prompt  removal  of  cows  suffering  with  garget  from  the  herd  was 
advised,  and  warning  was  given  that  these  sick  cattle  should  not  be  milked 
or  otherwise  cared  for  by  the  attendants  of  the  milking  herd.  The  prac- 
tice of  milking  the  fore-milk  onto  the  stable  floor,  Bergey  condemned 
because  of  the  likelihood  of  its  spreading  infection. 

Hastings  and  Hoffman  studied  the  bacterial  content  of  milk  from  the 
udders  of  individual  cows.  The  result  of  their  observations  on  two  that 
gave  high  counts  and  one  that  gave  low  ones  are  presented  in  Table  41. 

TABLE  41. — BACTERIAL  COUNT  OF  THE  MILK  FROM  THE  UDDER  OF  THREE  Cows 

(HASTINGS  AND  HOFFMAN) 


Cow 

Days 
sampled 

Average  num- 
ber bacteria  per 
cubic  centi- 
meter 

Maximum  number 
of  bacteria  per 
cubic  centi- 
meter 

Minimum  number 
of  bacteria  per 
cubic  centi- 
meter 

Number  of  samples 
running  over   1,000 
bacteria  per  cubic 
centimeter 

Brownie...  . 

61 

31,000 

305,000 

1,700 

50 

Dorine  

33 

191,000 

3,500,000 

2,500 

28 

Merney  

27 

810 

4,250 

50 

0 

In  the  case  of  Brownie  and  Dorine  the  high  number  of  bacteria  was 
due  largely  to  the  presence  of  a  single  kind  of  organism,  a  streptococcus 
similar  to,  or  identical  with  St.  pyogenes.  In  the  case  of  Merney  the  bac- 


SANITARY  MILK  PRODUCTION  147 

teria  were  almost  entirely  yellow  and  white  cocci.  It  was  the  opinion  of 
the  authors  that  the  average  bacterial  content  of  milk  from  the  udders  of 
healthy  cows  is  not  over  1,000  bacteria  per  cubic  centimeter;  they  figure 
that  the  presence  of  one  Dorine  in  a  herd  of  16  cows  would  treble  the 
bacterial  count  and  they  suggest  that  the  removal  of  such  a  cow  from  a 
herd  producing  certified  milk  might  be  desirable. 

Harding  and  Wilson  studied  the  bacterial  flora  of  cows'  udders;  their 
discussion  of  the  topic  is  based  on  the  quantitative  relationships  of  1,274 
samples  representing  83  cows  and  on  the  qualitative  findings  from  900 
samples  representing  63  cows.  They  found  that  many  forms  that  occur 
in  the  udder  are  so  accustomed  to  relatively  high  temperatures  that  they 
do  not  develop  well  on  culture  media  at  room  temperature. 

There  are  most  bacteria  in  the  fore-milk;  in  the  main  portion  of  the 
milking  there  are  distinctly  less,  while  the  milk  of  the  strippings  contains 
an  intermediate  quantity  and  in  fact  shows  numbers  closely  approximate 
to  the  germ  content  of  the  entire  flow  of  milk.  Samples  of  the  strippings 
are  very  satisfactory  for  studying  the  udder  flora. 

An  examination  of  1,230  samples  from  78  cows  averaged  428  bacteria 
per  cubic  centimeter.  There  were  about  three  times  as  many  bacteria  in 
the  fore  as  in  the  hind  quarters;  the  factor  controlling  this  distribution 
was  not  found.  Only  about  8  per  cent,  of  the  samples  examined  had  more 
than  1,000  germs  per  cubic  centimeter  and  the  authors  concluded  that  the 
average  germ  content  in  the  milk  which  could  be  regarded  as  having  been 
derived  from  the  udder  were  500  per  cubic  centimeter. 

Neither  the  age  of  the  cow  nor  the  period  of  lactation  exerted  any 
decided  influence  upon  the  germ  content  of  the  milk  of  the  udder. 

When  classified  according  to  the  system  of  the  Society  of  American 
Bacteriologists  the  organisms  found  in  about  900  samples  fell  into  71 
groups.  No  organisms  producing  spores  and  no  motile  forms  were  found. 

In  contrast  to  the  experience  of  Harding  and  Wilson  in  isolating  but 
two  streptococci  from  63  cows  is  that  of  Sherman  and  Hastings  who  in 
the  milk  of  88  animals  in  four  herds  demonstrated  streptococci  in  38.6  per 
cent,  of  the  samples.  The  animals  in  three  of  the  herds  were  examined 
but  once,  while  those  of  the  fourth  herd  were  tested  several  times.  These 
authors  say  they  are  certain  that  if  milk  is  to  be  condemned  because 
of  the  presence  of  udder  streptococci  a  very  considerable  portion  of  milk- 
producing  animals  would  have  to  be  removed  from  the  herds. 

The  fact  that  streptococcic  infections  are  very  common  sjiould  be 
borne  in  mind  by  health  officers  who  are  investigating  epidemics  of  septic 
sore  throat.  That  such  epidemics  may  arise  from  streptococcic  infections 
of  the  udder  is  true  but  there  is  not  necessarily  any  relation  between 
streptococci  found  in  the  udder  and  those  isolated  from  patients  having 
the  disease.  Proof  of  their  identity  is  demanded. 

The  most  illuminating  study  of  the  udder  bacteria  is  that  of  Evans. 


148  CITY  MILK  SUPPLY 

She  examined  the  milk  of  five  herds  of  cows  stabled  in  modern  clean 
barns;  three  herds  were  in  the  vicinity  of  Washington,  D.  C.,  and  two  sup- 
plied certified  milk  to  Chicago.  Special  methods  of  isolating  and  study- 
ing the  bacteria  were  developed.  In  all,  192  samples  of  milk  from  161 
cows  were  examined.  The  intention  was  to  consider  only  cultures  which 
were  capable  of  multiplying  in  the  udder  and  becoming  localized  there 
and  so  no  attention  was  given  to  types  which  occurred  in  small  numbers. 
Altogether  32,  or  16.1  per  cent.,  of  the  192  samples  were  from  quarters  of 
the  udder  in  which  the  bacteria  were  not  multiplying  in  numbers  worth 
considering.  Three  types  of  microbes,  viz.,  streptococci,  staphylococci 
and  bacteria  were  found. 

In  studying  the  streptococci  a  most  important  distinction  was  made 
between  two  groups,  namely:  (1)  the  long-chained  streptococci  which 
curdle  litmus  milk  and  partially  decolorize  it  thereafter;  and  (2)  St. 
lacticus  which,  prior  to  curdling,  produces  complete  decolorization  be- 
neath a  pink  layer.  St.  lacticus  was  not  found  in  any  of  the  samples 
of  milk  which  indicates  that  it  does  not  localize  and  multiply  in  the 
udder.  The  long-chained  streptococci  were  isolated  from  29,  or  15.1 
per  cent.,  of  the  whole  number  of  samples.  The  highest  number  found 
per  cubic  centimeter  was  264,000. 

The  micrococci  were  the  most  frequent  components  of  the  udder  flora; 
they  were  found  in  113,  or  58.8  per  cent.,  of  the  whole  number  of  samples, 
the  highest  .number  per  cubic  centimeter  being  80,000.  The  majority 
of  the  micrococci  belonged  to  a  single  group  which  agrees  with  the  pyo- 
genic  staphylococci.  The  majority  of  the  cultures  of  this  group  were  non- 
virulent  but  two  were  highly  virulent  to  rabbits.  To  a  second  group  no 
name  was  given  because  of  the  small  numbers  of  cultures  studied.  A  third 
group  was  identified  with  M.  luteus.  A  fourth  group  was  characterized 
by  rapid  and  complete  peptonization  of  the  milk;  hence  it  was  named 
M.  caseolyticus. 

Bacteria  of  peculiar  strains  of  types  commonly  present  in  freshly 
drawn  milk,  were  sometimes  found  localized  in  the  udder  of  several  cows 
of  one  dairy  and  a  few  cases  were  found  of  peculiar  species,  unlike  any  of 
the  udder  organisms,  being  localized  in  the  udders  of  several  cows  of  one 
dairy.  The  Bacilli  commonly  present  in  milk  from  all  dairies  were  shown 
to  be  related  to  Bad.  abortus.  Three  varieties  of  this  type  were  distin- 
guished. The  variety  of  Bad*  abortus  occurring  most  frequently  in  the 
samples  0f  milk  was  designated  Bact.  abortus,  var.  lipolyticus  because  it 
decomposes  butterf at ;  it  agrees  closely  in  its  culture  characteristics  with 
Bang's  original  description,  of  Bact.  abortus.  Cultures  of  this  variety 
were  shown  to  be  capable  of  imparting  undesirable  flavors  and  odors  to 
cream  kept  under  conditions  such  as  those  to  which  it  often  is  subjected. 
Other  varieties  of  the  Bact.  abortus  type  differed  considerably^  from  the 
lipolyticus  variety  but  resembled  cultures  isolated  from  pathogenic 


SANITARY  MILK  PRODUCTION  149 

sources.  Cultures  of  the  Bad.  abortus  type  were  isolated  from  45,  or 
23.4  per  cent.,  of  the  192  samples  of  milk  studied;  the  highest  number 
found  per  cubic  centimeter  was  50,000. 

From  the  study  Evans  concluded  that  there  is  a  definite  udder  flora 
comprising  bacteria  which  belong  to  the  parasitic  type.  She  remarks 
that  it  is  not  surprising  to  find  the  organisms  of  the  same  type  as  those 
common  on  the  skin  and  mucous  membranes  of  man  and  animals.  The 
majority  of  the  organisms  on  the  skin  are  non-pathogenic  but  there  are 
some  virulent  forms  and  similarly  the  majority  of  those  in  the  udder  appear 
to  be  harmless  but  organisms  virulent  to  the  lower  animals  were  isolated. 
While  the  pathogenic  properties  of  the  organisms  from  the  udder  are  not 
discussed  in  this  paper  as  a  whole  the  data  presented  constitute  a  valid 
argument  for  the  pasteurization  of  all  milk. 

Besides  harmless  microbes,  milk  from  the  udder  at  times  contains  the 
germs  of  disease.  Cows  with  tuberculous  udders  secrete  milk  that  con- 
tains large  numbers  of  tubercle  bacilli  that  are  infectious  to  both  humans 
and  calves.  Cows  sick  with  anthrax  yield  milk  containing  anthrax 
bacilli  and  the  milk  of  cows  with  the  trembles  has  often  proved  fatal  to 
those  who  have  partaken  of  it.  Barber's  proof  that  a  staphylococcus 
isolated  in  the  milk  fresh  from  the  udder  of  a  cow  was  the  cause  of  many 
cases  of  gastro-enteritis  shows  that  organisms  that  are  not  recognized  as 
disease  germs  may  at  times  cause  severe  sickness. 

Fecal  Contamination  of  Milk. — The  fecal  and  urinary  discharges  of 
cows  for  the  sake  of  decency  should  be  kept  out  of  milk;  the  very  idea  of 
their  presence  is  abhorrent.  Both  may  be  the  cause  of  disease ;  it  is  known 
that  they  may  transmit  tuberculosis  and  other  maladies,  particularly  the 
intestinal  disturbances  of  infants  and  less  frequently  of  adults,  are  at- 
tributed to  the  use  of  milk  heavily  polluted  with  animal  excrement 
though  the  specific  exciting  organisms  may  not  be  known.  Of  course 
cows  are  constantly  defecating  and  urinating  and  some  of  the  matter 
passed  adheres  to  the  coat  and  will  fall  into  the  milk  unless  cleanly 
methods  of  milking  are  used.  Bacteria  of  the  B.  coli-Bact.  lactis  aerogenes 
group  occur  abundantly  in  feces.  They  are  likely  to  form  a  gassy  curd 
and  also  to  produce  an  offensive  odor  and  a  disagreeable  taste  in  milk  and 
in  cream  soured  by  their  action,  consequently  they  impair  milk  for  cheese 
making  and  for  the  city  milk  trade  and  cream  also  for  use  in  manufactur- 
ing butter.  So  both  to  protect  the  public  health  and  for  strictly  commer- 
cial reasons  everything  should  be  done  to  check  fecal  contamination  of 
milk. 

Contamination  of  Milk  by  Discharges  from  the  Nose  and  Mouth. — 
The  nasal  and  buccal  discharges  of  cattle  are  the  source  of  bacterial  con- 
tamination of  milk.  St.  lacticus,  which  is  the  cause  of  ordinary  milk 
souring,  Esten  has  pointed  out  is  always  present  in  large  numbers  in  the 
cow's  mouth,  consequently  in  licking  herself  she  transfers  them  to  her 


150  CITY  MILK  SUPPLY 

coat  from  which  they  find  their  way  into  the  milk.  These  germs  are 
beneficial  to  the  dairy  industry  because  they  cause  milk  to  decompose  in 
the  normal  way  and  because  they  play  a  necessary  part  in  the  manufac- 
ture of  butter  and  other  dairy  products,  but  there  are  also  in  the  droolings 
and  nasal  discharges  of  cows  sick  with  certain  diseases  germs  that  may 
infect  man,  consequently  the  possibility  of  their  causing  trouble  should 
be  borne  in  mind. 

Contamination  of  Milk  from  the  Coat  of  the  Cow. — The  cow  is  a  neat 
animal  and  when  she  is  out  of  doors,  unless  she  is  pastured  on  marshy 
lands  or  kept  in  an  undrained  barnyard,  the  wind  and  rain  keep  her  coat 
clean  but  if  she  is  confined  in  the  barn  she  will  get  very  dirty  unless  care- 
fully cared  for.  The  dirt  that  collects  on  her  coat  is  made  up  of  fecal 
matter,  dust  from  the  hay  and  all  sorts  of  substances  with  which  she  comes 
into  contact.  It  dries  on  the  hairs  of  her  coat  and  is  readily  dislodged. 
Pains  must  be  taken  to  prevent  this  dirt  falling  into  the  milk  during 
milking.  This  is  best  accomplished  by  keeping  the  cow  as  clean  as  possi- 
ble; she  should  be  curried  long  enough  before  milking  to  give  the  dust 
time  to  settle.  Then  she  should  be  tied  in  such  a  way  that  she  cannot  lie 
down  until  after  milking  is  done.  Currying  of  the  cow  and  wiping  her 
udder  may  be  made  easier  by  clipping  her  belly,  udder  and  hind  quarters. 
Before  milking  is  begun  the  udder  should  be  washed  in  lukewarm  water 
and  then  partially  dried  with  a  clean  cloth.  This  removes  loose  hairs, 
particles  of  skin  and  dirt  that  otherwise  would  fall  from  the  udder  as  it  is 
manipulated  in  milking.  The  washing  and  wiping  of  the  udder  should  be 
done  thoroughly.  Care  should  be  taken  not  to  spread  garget  and  other 
contagions  in  the  herd  by  using  cloths  on  other  animals  that  have  been 
used  on  sick  ones.  The  bacteria  that  get  into  milk  from  the  coat  are  of 
many  sorts;  the  germs  that  are  most  undesirable  are  members  of  the  B. 
coli-Bact.  lactis  aerogenes  group  which  come  from  the  manure  and  those 
of  the  B.  subtilis  group  which  come  from  the  hay  and  dust.  Members  of 
the  latter  group  decompose  protein  often  with  the  production  of  vile 
odors;  they  sometimes  cause  the  sweet  curdling  of  milk,  and  according 
to  Rosenau  their  presence  in  excessive  numbers  has  often  caused  gastro- 
intestinal disturbances  in  children. 

Wolf  and  Weighmann  demonstrated  that  the  bacteria  on  the  leaves 
of  certain  pasture  plants  were  identical  with  those  that  occasionally 
affect  milk  injuriously  so  that  they,  and  also  Ernst,  believe  that  cows 
in  pasture,  at  times  infect  their  coats  with  bacteria  from  plants,  with 
the  result  that  when  the  cows  are  milked  these  bacteria  get  into  the  milk 
and  cause  unpleasant  flavors. 

Small-top  Milk  Pails. — To  reduce  the  numbers  of  bacteria  that  get 
into  milk  from  the  coats  of  animals  and  from  other  sources  in  milking, 
small-top  milk  pails  should  be  used.  The  first  that  were  introduced 
were  badly  designed,  or  were  fussy  contraptions  that  met  with  little 


SANITARY  MILK  PRODUCTION  151 

favor  but  these  pails  have  been  simplified  and  made  practical  so  that 
there  can  be  no  reasonable  objection  to  their  use. 

According  to  Harding,  Wilson  and  Smith,  Dr.  R.  G.  Freeman  was 
the  first  to  see  the  advantages  of  the  small-top  pail.  He  tried  to  intro- 
duce it  at  the  Fairfield  Dairy  in  1895  but  without  success.  It  was  seen 
in  use  there  by  S.  M.  Shoemaker  who  adopted  it  in  his  Burnside 
Dairy  at  Eccleston,  Md.  The  Freeman  pail  was  difficult  to  use  and  to 
clean  so  that  it  was  never  popular.  The  Gurler  pail  which  was  brought 
out  by  H.  B.  Gurler  of  De  Kalb,  111.,  about  1895,  was  more  successful. 
The  Stadmuller  pail  made  by  F.  H.  Stadmuller  of  West  Hartford,  Conn., 
was  the  next  to  attract  attention;  for  some  time  it  was  in  daily  use  in 
the  Storrs  Agricultural  Experiment  Station.  A  host  of  small-top  pails, 
some  of  them  highly  impractical,  followed.  Among  the  patterns  that 
survived  are  the  Storrs  pail  designed  by  J.  M.  Trueman  of  the  Storrs 
Agricultural  Experiment  Station,  the  Amherst  pail  and  the  improved 
Loy  pail  made  by  Harry  Loy  of  Geneva,  N.  Y.  A  pail  that  has  met  with 
considerable  favor  because  of  its  convenience  for  the  milker  is  the  Cleano, 
made  by  C.  E.  Tyler  of  Rome,  N.  Y. 

The  milk  hod  seems  to  have  been  invented  at  Shoemaker's  Burnside 
Dairy,  where  it  is  in  use,  and  modifications  of  it  by  Charles  E.  North 
and  by  Stephen  Francisco,  Jr.,  have  been  brought  out  as  the  North 
and  as  the  Francisco  milk  hods. 

Some  bacteriological  studies  of  the  value  of  small-top  milk  pails 
were  made  by  Freeman  and  by  Conn  but  the  first  extensive  experiments 
were  those  of  Stocking  in  1901.  They  indicated  the  great  value  of  such 
pails  and  led  to  the  doing  away  with  the  strainers  that  were  a  part  of  the 
pails  then  in  use,  for  it  was  shown  that  the  dirt  that  lodged  on  them  was 
beaten  up  and  forced  through  them  into  the  milk  by  the  streams  of  milk 
from  the  teat.  Stocking  continued  his  studies,  experimenting  with  the 
Stadmuller,  Haymaker,  North  and  Gurler  pails  and  in  Bulletin  48  of  the 
Storrs  Experiment  Station  summarized  the  results  of  his  work.  Among 
other  things  he  concluded  that  the  small-top  pail  excludes  much  dirt 
and  many  bacteria  from  milk,  that  the  shape  of  the  pail  and  of  the  top 
is  not  important  provided  the  pail  is  convenient  to  use  and  has  a  top  with 
an  opening  as  small  as  may  be  without  making  milking  difficult. 

Harding,  Wilson  and  Smith  in  1910  published  the  results  of  their 
studies  on  the  small-top  pail.  They  experimented  with  eight  different 
pails  with  small  tops,  and  reached  the  conclusion  that  the  pails  should 
not  be  over  12  in.  high  and  should  have  elliptical  rather  than  round  open- 
ings, because  that  shape  is  easier  to  milk  into  and  may  be  smaller  than 
a  round  one,  an  opening  5  by  7  in.  sufficing.  The  cover  should  be 
flush  with  the  top  of  the  pail  in  order  to  avoid  a  groove  that  will  lead  dirt 
from  the  top  into  the  milk  and  should  be  convex  that  the  pail  may  be 
easily  cleaned.  They  found  that  more  than  half  the  contamination  milk 


152  CITY  MILK  SUPPLY 

receives  at  milking  can  be  prevented  by  the  use  of  the  small-top  pail. 
A  defect  in  many  of  the  covered  pails  is  the  lack  of  a  ridge  around  the 
opening  to  prevent  dirt  rolling  from  the  top  of  the  pail  into  the  milk. 

Milking  Machines. — The  drudgery  of  milking  has  deterred  many  a 
farmer  from  entering  dairying  and  the  increasing  cost  of  farm  labor  has 
made  employers  anxious  to  economize  in  its  employment.  So  of  recent 
years  there  has  been  much  experimenting  with  milking  machines.  As 
early  as  1819  inventors  were  endeavoring  to  produce  a  successful  me- 
chanical milker  but  it  was  not  till  the  appearance  of  the  Lawrence- 
Kennedy  machine  in  1902  that  a  measurably  successful  one  was  pro- 
duced. Since  that  time  advance  has  been  rapid  and  at  the  present  time 
there  are  several  milkers  on  the  American  market;  among  them  are  the 
Burrell-Lawrence-Kennedy  or  B-L-K,  the  Sharpies,  the  Calf-way  and 
the  Empire.  Harding  has  pointed  out  that  these  and  all  other  successful 
machines  operate  on  the  suction  principle,  imitating  the  calf  which  wraps 
its  tongue  around  the  teat,  presses  it  slightly  and  forms  a  vacuum  thereby 
producing  a  suction  which  releases  the  sphincter  muscle  of  the  teat  and 
withdraws  the  milk.  The  calf  does  not  suck  steadily  but  gives  about  40 
sucks  a  minute  so  that  the  application  of  the  vacuum  is  intermittent. 
In  the  early  machines  the  vacuum  was  continuous  and  it  was  not  till 
Shiels  conceived  the  idea  of  admitting  air  to  produce  vacuum  pulsations 
that  encouraging  results  were  obtained.  This  idea  was  perfected  by 
Lawrence  and  Kennedy. 

It  has  been  the  object  of  manufacturers  to  produce  milkers  of  low  first 
cost  which  should  be  economical  and  simple  to  operate,  which  would  not 
injure  the  cows,  which  would  milk  so  clean  that  it  would  be  unnecessary 
to  milk  out  the  strippings  by  hand  and  which  would  deliver  milk  of  low 
germ  content.  Varying  degrees  of  success  have  attended  the  efforts  to 
attain  these  results.  With  regard  to  the  production  of  sanitary  milk, 
the  machines  were  at  first  a  great  disappointment  but  at  the  several 
experiment  stations  where  they  were  installed  for  study  showed  that  the 
principal  sources  of  contamination  were:  (1)  the  air  that  was  admitted 
to  the  teat  cup;  (2)  the  soiling  of  the  cups  by  careless  handling  and  drop- 
ping them  on  the  floor;  and  (3)  the  rubber  parts  which  were  difficult 
to  clean  after  milking. 

The  air  contamination  was  easily  prevented  by  filtering  the  air  through 
cotton  before  admitting  it  to  the  cups.  The  contamination  that  results 
from  dropping  the  cups  can  be  avoided  only  by  handling  them  carefully 
in  the  stable.  The  contamination  from  the  imperfectly  cleaned  rubber 
parts  was  difficult  to  cope  with.  It  was  soon  seen  that  the  parts  would 
not  only  have  to  be  thoroughly  washed  but  that  they  would  have  to  be 
kept  when  not  in  use  in  some  antiseptic  solution.  After  considerable 
experimentation  common  salt,  lime  water  and  bleaching  powder  have 
been  found  suitable  for  the  purpose.  The  common  practice  now  is  to 


SANITARY  MILK  PRODUCTION  153 

rinse  out  the  cups  and  rubber  connections  in  cold  or  tepid  water  after 
which  they  are  thoroughly  washed  in  a  hot  solution  of  washing  powder 
and  rinsed  in  clean  water.  Then  they  are  kept  in  an  antiseptic  or  a 
germicidal  solution,  preferably  of  chloride  of  lime  or  bleach.  In  putting 
the  tubing  into  the  antiseptic,  great  care  must  be  taken  that  air  pockets 
do  not  form  and  prevent  the  solution  coming  into  contact  with  the  rubber. 
When  the  rubber  parts  are  needed  they  are  carefully  rinsed  in  clean  fresh 
water  before  using  them.  The  buckets  into  which  the  milk  flows  should  be 
washed  after  milking  and  sterilized  with  steam  before  being  used  again. 

An  objection  that  has  been  raised  to  the  use  of  milking  machines  is 
that  if  a  high  vacuum  was  inadvertently  used  the  cellular  content  of 
the  milk  might  be  increased  or  that  blood  might  be  drawn  from  the 
udder.  Breed  has  found  these  fears  groundless  but  advises  the  use  of 
the  low  vacuum  recommended  by  the  makers. 

The  point  has  been  made  that  in  machine  milking  incipient  udder 
trouble  is  more  likely  to  escape  attention  than  in  hand  milking  because 
the  udder  is  handled  less.  This  is  most  likely  to  happen  where  two  cows 
are  milked  into  a  bucket  having  a  single  compartment  for  slight  abnor- 
mality in  the  milk  is  apt  to  pass  unnoticed.  Also  fear  has  been  expressed 
that  garget  might  be  spread  in  the  herd  by  the  teat  cups.  In  practice 
this  does  not  seem  to  have  been  a  serious  matter. 

A  factor  that  has  operated  to  impede  the  introduction  of  all  types 
of  milking  machines  is  that,  though  they  are  not  too  complicated  for 
intelligent  dairymen  to  handle,  far  more  mechanical  ingenuity  and  depend- 
ability than  the  average  dairy  hand  has,  is  required  to  operate  them 
successfully;  so  it  is  necessary  to  employ  a  man  who  commands  higher 
wages. 

Contamination  of  Milk  in  Straining. — It  seems  to  be  the  opinion  of 
many  dairymen  that  it  matters  little  whether  dirt  gets  into  milk  or  not, 
because  it  can  be  strained  out  later.  At  all  events,  in  many  dairies  a 
deal  of  time  is  spent  straining  milk.  Of  course  it  is  known,  since  manure 
and  other  dirt  that  gets  in  milk  is  partially  soluble,  that  all  of  it  cannot 
be  removed  in  this  way  but  it  is  natural  to  think  that  the  milk  will  be 
better  for  having  the  visible  dirt  strained  out.  Careful  experimentation 
shows  that  no  great  amount  of  improvement  is  effected  in  this  way. 
Conn,  Stocking  and  many  others  have  studied  the  matter  and  gotten 
results  that  are  substantially  the  same. 

Stocking  determined  the  bacterial  content  of  five  samples  of  milk, 
passed  them  through  three  thicknesses  of  fine  cheese  cloth,  supported 
on  wire  gauze  and  then  determined  the  count  of  the  filtered  milk.  The 
results  which  are  those  given  in  Table  42  are  such  as  are  obtained  when 
milk  is  carefully  filtered  through  cheese  cloth  into  clean  vessels,  and  the 
effect  of  filtering  is  therefore  shown  most  favorably. 


154  CITY  MILK  SUPPLY 

TABLE    42. — EFFECT  ON  THE   BACTERIAL   COUNT  OF  STRAINING   MILK  THROUGH 

CHEESE  CLOTH  (STOCKING) 


Samples 

Number  of  bacteria  per  cubic  centi- 
meter before  straining 

Number  of  bacteria  per  cubic  centi- 
meter after  straining 

1 

3,600 

3,600 

2 

7,400 

6,900 

3 

12,800 

10,500 

4 

8,800 

11,375 

5 

8,000 

2,200 

Five  other  samples  were  filtered  in  the  same  way  and  the  keeping 
power  of  the  filtered  and  unfiltered  portions  compared,  with  the  result 
that  it  was  found  that  the  keeping  quality  of  none  of  the  milk  was  im- 
proved by  filtering  and  that  of  some  was  impaired.  The  use  of  strainer 
cloths  on  the  farm  probably  has  a  bad  effect,  for  they  are  commonly  used 
again  and  again  without  being  boiled  out  and  dried  quickly  every  time 
they  are  used;  hence  they  seed  the  milk  with  bacteria.  Moreover,  when 
the  filters  clog,  the  milkers  are  prone  to  poke  them  and  so  contaminate 
the  milk  with  their  fingers. 

Influence  of  the  Cream  Separator  on  the  Bacterial  Count  of  Cream 
and  Skim-milk. — Milk  can  be  skimmed  and  clarified  by  centrifugal 
force.  On  the  farm,  cream  separators  are  used  for  skimming  the  milk 
and  also  to  some  extent  for  clarifying  it.  In  city  milk  plants  clarification 
is  accomplished  by  specially  designed  centrifugal  clarifiers. 

By  the  use  of  cream  separators  the  bacterial  count  of  the  milk  is 
increased  in  two  ways,  namely :  by  the  actual  addition  of  more  germs  to 
the  milk,  by  contact  with  the  insterile  parts  of  the  separator  through 
which  it  passes;  and  second,  by  the  breaking  up  of  bacterial  clumps 
and  chains  as  the  milk  passes  through  the  machine.  Of  these  two,  the 
former  is  the  more  important  when  the  cleaning  of  the  separator  is  ha- 
bitually slighted.  The  breaking  up  of  the  clusters  and  chains  most  notice- 
ably increases  the  number  of  bacteria  when  the  milk  being  separated  or 
clarified  has  a  high  count.  In  the  passage  of  the  milk  through  the  sepa- 
rator, part  of  the  germs  go  with  the  cream,  part  with  the  skimmed  milk, 
and  part  are  thrown  out  with  the  slime.  Apparently  the  percentage  of 
bacteria  that  goes  to  each  varies,  for  conflicting  results  have  been  ob- 
tained by  different  experimenters.  Most  find  that  after  separation 
both  the  skim-milk  and  the  cream  contain  more  bacteria  than  did  the 
original  milk,  and  that  the  cream  contains  more  than  the  skim-milk  but 
that  both  contain  fewer  than  the  slime.  Possibly  a  distribution  after 
separation  of  25  per  cent,  of  the  bacteria  in  the  skim-milk,  28  per  cent, 
in  the  cream,  and  47  per  cent,  in  the  slime,  is  an  approximation  of  what 
may  be  expected  but  no  fixed  ratio  can  be  predicted.  Heinemann, 
Luckhart  and  Hicks  found  fewer  bacteria  in  the  separated  cream  and 


SANITARY  MILK  PRODUCTION 


155 


more  in  the  skim-milk  than  in  the  unskimmed  milk.  Heinemann  and 
Class  continuing  the  experiment  found  that  separated  cream  contains 
fewer  bacteria  than  the  milk  from  which  it  is  obtained,  that  the  number 
of  bacteria  in  separated  cream  decreases  proportionately  as  the  fat  con- 
tent increases  and  that  the  number  of  bacteria  in  separated  milk  is  larger 
than  the  number  in  the  milk  from  which  it  is  obtained,  if  the  cream  con- 
tains up  to  about  35  per  cent,  fat;  above  this  percentage  the  number  is 
smaller.  They  found,  too,  that  the  number  of  bacteria  in  separated 
milk  decreases  proportionately  with  increase  of  fat  in  separated 
cream. 

Cooling  of  Milk. — It  is  absolutely  essential  in  order  to  prevent  rapid 
bacterial  development  in  milk,  with  consequent  deterioration  thereof, 
that  it  be  cooled  promptly  after  milking.  On  most  farms  the  cooling 
is  done  by  setting  the  milk  in  a  tub  of  well  or  ice  water.  The  effective- 
ness of  this  method  is  shown  by  the  figures  in  Table  43. 

TABLE  43. — THE  COOLING  OF  CREAM  IN  CANS  (U.  S   DEPT.  OF  AGRICULTURE) 


Temperature  in  degrees  Fahrenheit  of 

Method  of  cooling 

Temperature 
of  cooling 
medium 

Temperature 
of  cream 

cream  at  later  periods 

H  hr. 

Ihr. 

2hr. 

3hr. 

4hr. 

5hr. 

6hr. 

7hr. 

8hr. 

Can  of  cream  placed  on 

cement  floor  in  cellar.  . 

62 

92.5 

90.5 

89.0 

87.0 

87.0 

85.  C 

80.5 

79.0 

78.0 

76.5 

Can  of  cream  placed  in 

cool  non-running  water 

52 

89.0 

86.7 

83.0 

76.7 

73.0 

70.0 

68.2 

67.0 

65.7 

65.0 

Can  of  cream  placed  in 

cool  running  water.  .  .  . 

52 

86.5 

83.8 

75.6 

65.1 

62.5 

60.5 

59.0 

58.0 

57.0 

56.1 

Can  of  cream  placed  in 

cool  running  water  and 

stirred  at  half-hour  in- 

tervals   

52 

85.5 

77.0 

68.4 

63.5 

60.5 

58.7 

57.5 

56.4 

55.5 

55.0 

Many  farmers  instead  of  cooling  milk  in  cans  bring  it  to  low  tempera- 
ture by  running  it  over  coolers.  They  are  of  various  sorts  but  in  all  of 
them  the  milk  is  cooled  by  flowing  in  a  film  over  an  extensive  surface  of 
thin  metal  which  is  chilled  by  cold  water  or  by  brine.  Coolers  work 
well  when  properly  cared  for  but  they  cannot  be  neglected  without 
injury  resulting  to  the  milk  for  it  flows  over  the  entire  surface  of  the 
cooler  and  consequently  picks  up  all  the  dirt  there  is  on  it.  Whenever 
steam  is  available  coolers  should  be  sterilized  immediately  before  use. 
In  watching  the  cooling  of  milk  one  sometimes  sees  it  refuse  to  flow  over 
a  part  of  the  cooler,  which  generally  indicates  that  the  spot  is  unclean. 
Milk  may  be  both  contaminated  and  adulterated  by  the  escape  of  water 
or  brine  from  a  leaky  cooler.  Besides  being  contaminated  by  the  cooler 
the  milk  may  be  also,  by  the  air,  if  the  cooler  is  an  open  one  and  the 
cooling  is  done  in  a  dusty  place.  If  the  room  is  malodorous  the  milk  may 


156 


CITY  MILK  SUPPLY 


acquire  an  off  flavor;  sometimes  the  operation  of  a  gasolene  engine  where 
the  cooling  is  being  done  will  impart  a  distinct  taste  to  the  milk. 

Aeration  of  Milk. — Formerly  much  store  was  set  by  aeration  as  a 
method  of  removing  odors  from  milk  and  in  improving  its  keeping  quality 
but  it  is  now  known  that  milk  from  healthy  cows  which  have  been  prop- 
erly fed  and  that  is  drawn  in  a  place  free  from  stenches  has  no  disagree- 
able smell.  Furthermore  such  improved  keeping  quality  as  resulted 
from  aeration  is  now  attributed  to  the  cooling  of  the  milk  in  the  process. 
So  this  fetish  is  not  so  fashionable  among  dairymen  as  it  once  was.  Such 
aeration  as  milk  now  receives  it  generally  gets  in  the  process  of  cooling 
but  that  aeration  of  first-class  milk  is  not  necessary  is  shown  by  some  of 
the  best  certified  milk  being  bottled  warm  and  cooled  afterward.  When 
warm  milk  is  put  into  cans  and  the  covers  put  on,  it  sometimes  happens 
that  bad  flavors  develop  but  this  is  believed  to  be  due  to  bacterial  growths 
that  are  favored  under  such  conditions  because  the  milk  has  not  been 
properly  cooled  rather  than  because  the  milk  was  not  aerated. 

Sometimes  milk  may  be  improved  by  aeration.  Ayres  and  Johnson 
have  pointed  out  that  the  garlic  flavor  so  common  in  milk  in  some  locali- 
ties where  the  animals  eat  the  wild  onion  in  pasture,  may  be  removed 
from  milk  and  cream  by  heating  them  to  145°F.  and  blowing  air  through 
under  pressure. 

Barn  Practices  in  Relation  to  Milk  Quality. — The  attempt  has  been 
made  to  estimate  the  relative  importance  of  the  common  barn  practices 
in  contaminating  milk.  Stocking  in  Bulletin  42  of  the  Storrs  Agricul- 
tural Experiment  Station  published  observations  on  the  effect  at  milking, 
of  feeding  cows,  of  brushing  them,  of  wiping  them  with  a  damp  cloth, 
of  rejecting  the  fore-milk  and  of  trained  as  compared  with  untrained 
milkers.  The  results  of  his  study  are  presented  in  Table  44. 

TABLE  44. — THE  EFFECT  ON  THE  BACTERIAL  COUNT,  OF  FEEDING,  OF  BRUSHING,  OF 
WIPING  Cows.  AND  OF  REJECTING  FORE-MILK  AT  MILKING  (STOCKING) 


Total  number 
of  bacteria 
per  cubic 
centimeter 

Acid  forming 
bacteria 
per  cubic 
centimeter 

Liquefying 
bacteria 
per  cubic 
centimeter 

Average  6  experiments,  before  feeding  hay  and  grain  

2,096 

790 

108 

Average  6  experiments,  after  feeding  hay  and  grain  

3,506 

1,320 

196 

Percentage  of  increase  due  to  feeding  

67.0 

67.0 

81.0 

Average  5  experiments,  before  feeding  dry  corn  stover  

1,233 

297 

1 

Average  5  experiments,  after  feeding  dry  corn  stover  

3,656 

692 

28 

Percentage  of  increase  due  to  feeding  

196.0 

133.0 

Average  14  experiments,  cows  not  brushed  before  feeding.  . 

1,207 

213 

59 

Average  14  experiments,  cows  brushed  before  feeding  

2,286 

381 

117 

Percentage  of  increase  due  to  brushing.  

89.0 

79.0 

98.0 

Average  13  experiments,  cows'  udders  and  flanks  not  wiped.  . 

7,058 

3,554 

81 

Average  13  experiments,  cows'  udders  and  flanks  wiped.  .  . 

716 

185 

47 

Percentage  of  decrease  due  to  wiping  

89.8 

94.7 

42.0 

Average  8  experiments,  fore-milk  not  rejected  

522 

189 

9 

Average  8  experiments,  fore-milk  rejected  

499 

99 

33 

Percentage  of  decrease  due  to  rejection  of  fore-milk 

4.4 

47.0 

SANITARY  MILK  PRODUCTION  157 

It  thus  appears  that  feeding  dry  and  dusty  feeds  at  milking  time 
increases  the  bacterial  count  materially  as  does  brushing  the  cows,  and 
that  wiping  the  cows  udders  and  flanks  decidedly  reduces  the  count. 
Rejecting  the  fore-milk  has  little  effect.  Experiments  showed  that  in 
order  to  exclude  the  fore-milk  of  high  germ  content  it  would  be  necessary 
to  waste  at  least  six  good-sized  streams  from  each  quarter,  an  amount 
that  means  considerable  loss.  Also,  it  was  shown  that  a  student  who  had 
some  bacteriological  training  could  milk  so  as  to  get  a  markedly  lower 
count  than  the  regular  milkers  who  lacked  this  training. 

Sterilizing  and  Protecting  the  Pails. — Harding,  Rhuele,  Wilson  and 
Smith  studied  the  effect  upon  the  germ  content  of  milk  of:  (1)  protect- 
ing milk  pails  by  tying  cloths  over  their  tops  before  sterilizing  them,  and 
not  removing  the  cloths  till  milking  was  actually  begun ;  (2)  of  the  effect 
of  plastering,  of  painting  and  of  whitewashing  the  stable;  (3)  of  clip- 
ping the  cows;  and  (4)  of  hand-  and  machine-cleaning  of  cows. 

In  the  experiment  on  the  effect  of  keeping  the  pails  covered,  tests 
were  made  on  6  days,  four  cows  being  used.  The  tests  were  so  conducted 
that  two  of  the  cows  were  milked  into  pails  that  had  been  sterilized  and 
kept  covered  till  milking  was  begun  and  two  were  milked  into  sterilized 
pails  that  were  brought  into  the  barn  uncovered  with  the  other  utensils, 
while  on  the  following  day  the  two  cows  that  had  been  milked  into  the 
pails  that  had  been  kept  covered  were  milked  into  those  that  were  not 
covered  and  the  other  cows  were  milked  into  those  that  had  been  covered 
over.  No  pails  were  used  more  than  once  at  a  milking.  At  every  milk- 
ing, samples  were  taken  from  each  pail  and  plated.  So,  in  the  series 
from  each  cow  there  were  three  samples  from  the  protected  and  three 
from  the  unprotected  pail  or  24  samples  altogether.  The  results  show  an 
average  count  of  922  bacteria  per  cubic  centimeter,  in  the  samples  from 
the  protected  pails,  and  2,391  on  those  from  the  unprotected,  or  an 
increase  of  160  per  cent,  due  to  exposure.  The  authors  regard  this  as 
important  though  they  point  out  that  the  influence  of  this  initial  con- 
tamination would  have  been  much  less  had  succeeding  cows  been  milked 
into  the  same  pail. 

Plastering,  Painting  and  Whitewashing. — The  authors  studied  the 
relationship  of  plastering,  painting  and  whitewashing  to  the  bacterial 
count  in  a  series  of  experiments  at  the  stable  of  the  New  York  Experi- 
ment Station  which  had  a  ceiling  of  beaded,  planed,  matched  southern 
pine,  and  walls  finished  in  the  same  material.  This  construction  is  not 
used  in  modern  barns  because  dust  accumulates  in  cracks  between  the 
boards  and  in  the  beading.  Dust  was  allowed  to  collect  on  walls,  ledges, 
and  stanchions  until  conditions  were  as  bad  as  would  be  tolerated  under 
reasonably  good  barn  management.  In  this  state  the  germ  content  of 
the  milk  of  each  of  six  cows  was  determined  at  six  separate  milkings. 
When  this  study  was  completed  the  ceiling  and  walls  of  the  stable  were 


158 


CITY  MILK  SUPPLY 


covered  with  wire  lath  and  two  coats  of  cement  down  to  within  3  ft. 
of  the  floor;  the  area  between  the  cement  and  the  floor  was  covered  with 
zinc.  In  putting  the  barn  in  order  after  plastering,  the  stanchions, 
floors  and  mangers  were  thoroughly  cleaned.  Then  milk  from  the  same 
six  cows  was  tested  again  on  6  days,  every  effort  being  made  to  keep  the 
barn  management  and  bacteriological  examination  identical  to  that  which 
obtained  in  the  unplastered  barn  except  that  in  this  series  of  tests  no 
dust  was  permitted  to  accumulate.  Next,  the  woodwork  and  ironwork 
of  the  stable  were  painted  and  a  series  of  six  tests  with  the  same  six 
cows  was  run  under  these  conditions.  A  summary  of  the  counts  ob- 
tained are  shown  in  Table  45. 

TABLE  45. — AVERAGE  GERM  CONTENT  OF  MILK  UNDER  VARIOUS  BARN  CONDITIONS 
(HARDING,  WILSON,  RUEHLE  AND  SMITH) 


Cow 

Before  plastering 

After  plastering 

After  painting 

Whole 
milk 

Strip- 
pings 

Dif- 
ference 

Whole 
milk 

Strip- 
pings 

Dif- 
ference 

Whole 
milk 

Strip- 
pings 

Dif- 
ference 

Millie  F 

2,271 
774 
293 
370 
468 
475 
775 

262 
321 
112 
93 
119 
178 
179 

2,009 
462 
181 
227 

348 
298 
596 

1,741 
1,298 
176 
337 
561 
1,164 
889 

245 
436 
17 
94 
108 
570 
249 

1,496 
861 
159 
243 
452 
594 
640 

906 
1,234 
83 
448 
265 
899 
656 

139 
220 
11 
184 
77 
535 
198 

766 
1,014 
72 
303 
188 
364 
459 

Nora  D  
Millie  F.  B.  B. 

ChloeB  
Carey  S.  F......  
Mabel  S.  F  
Genl.  average  

The  table  needs  little  explanation  further  than  to  state  that  the  figures 
in  the  columns  headed  difference  are  obtained  by  deducting  from  the 
bacteria  in  the  whole  milk  the  bacteria  in  the  strippings,  it  having  been 
found  by  the  authors  that  the  bacteria  in  the  strippings  fairly  represent 
the  number  of  bacteria  in  the  udder. 

In  commenting  on  the  results  from  the  212  samples  the  authors  point 
out  that  they  show  that  in  the  last  two  sets  of  tests  when  the  barn  was 
clean,  the  difference  in  germ  content  of  the  milk  was  greater  than  the 
difference  between  the  results  when  the  barn  was  clean  and  when  it 
was  dirty.  The  gist  of  the  matter  is  that  the  influence  of  these  barn 
conditions  upon  the  germ  content  of  the  milk  was  so  slight  that  it  was 
immeasurable. 

About  a  year  after  the  station  barn  was  plastered  a  series  of  tests  was 
made  to  determine  the  effect  of  the  whitewashing  of  a  barn  on  the  bac- 
terial count  of  milk  produced  in  it ;  the  experiments  were  suggested  by  an 
ordinance  that  is  found  in  many  health  codes  requiring  dairy  barns  to  be 
whitewashed  once  a  year  or  oftener.  For  20  successive  days  the  milk 
of  each  of  three  cows  was  sampled  and  plated.  Comparison  of  the 
results  shows  that  the  general  average  of  the  60  samples  taken  after  white- 


SANITARY  MILK  PRODUCTION 


159 


washing  was  a  trifle  higher  than  the  60  taken  before  but  the  difference 
is  not  great  and  as  a  whole  they  show  that  whitewashing  the  stable 
neither  raises  nor  lowers  the  bacterial  count  of  the  milk. 

Clipping  the  Cow's  Udders  and  Flanks. — The  effect  of  clipping  the 
cow's  udders  and  flanks  was  studied  and  the  results  obtained  are  presented 
in  Table  46. 

TABLE  46. — SUMMARY  OF  BACTERIAL  COUNTS,  EXPRESSED  IN  NUMBER  PER  c.c. 
OF  MILK  DRAWN  FROM  UNCLIPPED  AS  COMPARED  WITH  CLIPPED  Cows 


Carey  S.  F. 

Gertie  F.I.  B.B. 

Millie  F.B.B. 

Carey  S.  B.B. 

£ 

Q.  OB 

0) 
1     U 

id 

As 

«"  a 

,  s 

*g 

jd 

-N 

,  8 

Jt3  fl 

ju 

•II 

d§ 

£fa 

02  'ft 

_l 

£h 

£ft 

"1 

£ti 

02ft 

°i 

^h 

GG  ft 

0) 

Undipped  (ave.  22  samples')  on  each  cow 

158 

82 

76 

320 

81 

239 

142 

75 

67 

196 

46 

150 

Clipped  (ave.  24  samples)  on  each  cow.  . 

252 

145 

107 

470 

92 

378 

261 

73 

188 

298 

138 

160 

The  grand  average  of  all  the  samples  shows  that  the  undipped  cows 
had  204  bacteria  per  cubic  centimeter  in  the  whole  milk,  71  in  the  strip- 
pings  and  as  difference  133  whereas  the  clipped  cows  had  320  in  the  whole 
milk,  112  in  the  strippings  and  as  difference  208,  thus  showing  higher 
counts  in  the  milk  of  the  clipped  cows.  Moreover,  Table  46  shows  that 
in  every  instance  the  count  of  the  milk  of  the  four  cows  was  higher  when 
they  were  clipped  than  when  they  were  undipped.  In  explanation  of 
this  unlooked  for  result  the  experimenters  suggest  that  the  long  hairs 
retain  the  scurf  at  their  base  while  the  short  ones  do  so  less  effectively 
so  that  it  falls  into  the  milk  and  increases  the  bacterial  count. 

Hand-  vs.  Machine -cleaning  of  Cows. — The  same  authors  compared 
the  cleaning  of  cows  by  hand  with  cleaning  them  by  a  vacuum  cleaner 
and  found  that  the  latter  method  was  less  efficient  than  the  former 
when  the  vacuum  was  less  than  15  in.,  and  in  any  case  is  more  expensive 
since  it  takes  about  twice  as  long. 

Interpretation  of  the  New  York  Station  Experiments. — These  studies 
of  Harding  and  his  confreres  are  important  because  long  periods  of  con- 
tinuous sampling  were  employed  so  that  every  series  of  tests  is  a  fair 
measure  of  the  process  under  investigation  under  the  conditions  that 
obtained.  Nevertheless,  it  seems  likely  that  those  who  read  the  bulletin 
which  contains  the  results  may  draw  differing  conclusions  from  them. 
To  the  writer  it  seems  that  these  experimenters  have  shown  that  in  a 
barn  of  fair  construction  where  the  help  is  accustomed  to  pay  decent 
regard  to  cleanliness,  clean  milk  may  be  drawn  even  when  the  barn  is 
dirty  and  when  the  construction  is  such  as  would  not  be  recommended 
were  the  owners  building  anew.  They  also  show  that  plastering,  paint- 
ing and  whitewashing  do  not  directly  influence  the  bacterial  count. 
The  results  are  confirmatory  of  what  has  long  been  suspected.  Many 
dairy  men  are  known  to  produce  excellent  milk  in  barns  that  seem  un- 


160  CITY  MILK  SUPPLY 

suited  for  them  to  do  so.  The  question  then  arises  why  plastered  and 
painted  barns  have  superseded  those  of  matched  boards  and  why  health 
authorities  advise  whitewashing.  Speaking  by  and  large,  dirty  barns 
and  good  dairying  have  parted  company  forever;  barns  of  matched 
boards,  with  age,  become  dingy,  more  difficult  to  clean  and  give  trouble 
from  the  boards  separating.  The  plaster  finish  appeals  to  the  practical 
man  as  being  lighter,  brighter  and  more  easily  cared  for.  Then,  there  is 
this  difference  between  the  two  types,  the  wooden  barns  absorb  odors  so 
that  neglect  of  cleanliness,  or  even  long  use,  tends  to  give  them  a  decided 
odor  that  is  likely  to  be  unpleasant,  and  one  that  is  apt  to  be  acquired 
by  the  milk,  but  plaster  work  tends  to  neutralize  odors  rather  than  to 
store  them.  It  is  to  keep  the  barn  sweet  as  well  as  for  appearance  that 
the  woodwork  in  barns  is  painted.  Whitewashing  is  insisted  on  by 
boards  of  health,  chiefly  in  old  wooden  barns  as  a  means  of  lighting  them 
up,  so  that  better  work  will  be  done  in  them,  because  the  light  reflected 
from  the  white  walls  helps  one  to  see.  Also,  probably  whitewashing 
helps  to  keep  down  vermin  but  it  is  chiefly  useful  in  filling  the  pores  of 
the  wood  thereby  preventing  the  absorption  of  odors  and  making  the 
barns  better  smelling.  Putting  these  things  together  it  seems  that  the 
experiments  fortify  inspectors  with  reasons  for  permitting  men  of  small 
capital  and  those  serving  a  class  of  trade  than  cannot  afford  luxuries, 
to  continue  in  business  with  mediocre  equipment  provided  they  are 
actually  producing  good  milk,  but  where  the  diligence  to  succeed  under 
such  conditions  is  lacking  there  are  ample  reasons  for  requiring  the  plant 
to  be  improved  or  business  stopped.  Similar  experiments  are  desirable 
to  determine  if  possible  what  degree  of  dirtiness  must  obtain  in  the  dairy 
barn  to  raise  the  bacterial  count. 

The  writer  regards  as  interesting  the  fact  that  the  scurf  from  clipped 
cows  was  found  to  raise  the  count  above  that  of  the  milk  of  the  carefully 
cleaned,  undipped  ones  but  he  believes  that  in  practice  cows  will  con- 
tinue to  be  clipped  because  in  that  condition  they  are  easier  to  clean  and 
consequently  will  be  more  thoroughly  cleaned  than  they  would  be  were 
they  left  with  long-haired  udders  and  flanks. 

The  Open  Stable  and  the  Germ  Content  of  Milk.— In  the  States  of 
the  Union  that  have  a  mild  winter  there  are  in  use  open  stables  for 
housing  cattle.  There  is  a  tendency  for  the  germ  content  of  the  air  of 
closed  cow  stables  to  be  higher  in  winter  than  summer,  because  of  the 
closer  confinement  of  the  cows  and  the  use  of  dry  feeds  and  bedding  that 
fill  the  air  with  more  or  less  dust.  So  it  seems  that  milk  drawn  in  the 
separate  milking  room  of  an  open  stable  might  contain  fewer  bacteria 
than  that  drawn  in  a  closed  stable.  A  brief  series  of  experiments  to 
determine  the  matter  was  conducted  by  Lamson  at  the  Maryland  Agri- 
cultural Experiment  Station.  While  his  data  were  too  limited  to  permit 
him  to  draw  definite  conclusions,  they  indicated  that  the  germ  content 


SANITARY  MILK  PRODUCTION  161 

of  the  air  of  the  milking  room  of  the  open  stable,  was  less  than  that  of 
the  closed  barn;  that  fecal  contamination  of  the  milk  from  cows  kept 
in  the  open  stable,  where  the  cows  receive  little  attention,  was  no  greater 
than  in  closed  stables,  where  they  receive  a  good  deal,  and  that  there  is 
advantage  in  the  open  stable  as  a  place  to  produce  milk  of  low  germ 
content. 

Milk  is  polluted  by  bacteria  derived  from  dust  and  from  many 
sources  in  the  immediate  environment  of  the  stable  and  other  places 
where  it  is  handled  most.  Among  these  sources  of  pollution  are  the  air, 
the  feed,  the  bedding,  utensils  of  various  sorts  and  the  milkers. 

Air -borne  Contamination. — The  belief  in  air-borne  diseases  has  been 
held  for  many  centuries  and  from  the  early  days  of  bacteriology  until 
very  recently  air  was  believed  to  be  an  important  factor  in  transmitting 
contagion,  but  more  complete  understanding  of  microbial  life  has  shown 
that  while  germs  do  float  in  the  air,  air-borne  infection  is  not  to  be  greatly 
dreaded.  There  is  of  course  a  great  difference  in  air  as  to  the  germ  con- 
tent; some  is  very  dusty  and  carries  many  bacteria  while  other  air  is 
very  clean  and  nearly  germ-free.  It  may  be  advisable  to  filter  or  wash 
the  air  that  comes  into  a  milk  plant  located  on  a  dusty  city  street,  but 
wholly  unnecessary  to,  that  of  one  in  the  country.  Also,  some  dust 
may  be  rather  heavily  polluted  with  animal  excretions  while  other  may 
be  only  slightly  so.  In  any  case  it  is  the  visible  and  invisible  dirt  that 
floats  in  the  air  which  is  the  cause  of  bacterial  contamination  and  not 
the  air  itself,  for  the  germs  are  attached  to  dust  particles,  though  not  to 
all  of  them  for  some,  as  for  instance  those  of  soot,  are  sterile  and  all  the 
motes  that  float  in  the  air  tend  to  become  so  by  drying  and  the  germicidal 
action  of  sunlight. 

At  the  New  York  Experiment  Station  Rhuele  and  Kulp  have  made  a 
careful  quantitative  study  of  how  the  germ  content  of  the  stable  air 
affects  milk.  As  a  whole  their  results  show  that  the  microbial  con- 
tamination that  milk  derives  from  standing  in  the  air  of  a  well-kept  barn 
is  unimportant.  Out  of  54  tests  in  the  station  barn  there  were  but  17 
that  showed  the  number  of  precipitating  bacteria  to  be  greater  than  100 
per  square  centimeter  in  a  5-min.  interval,  and  the  highest  of  these  was 
only  269  per  square  centimeter.  Many  of  these  tests  were  made  when 
the  barn  air  was  disturbed  by  the  feeding  of  silage,  the  brushing  of  cows, 
etc.  Even  during  the  worst  of  these  conditions,  an  open  pail  of  milk 
could  have  stood  15  min.  in  the  stable  without  a  detectable  increase 
in  the  bacterial  content  of  the  milk  occurring. 

A  brief  exposure  of  the  milk  to  the  very  dusty  atmosphere  that 
prevailed  for  short  intervals,  during  certain  barn  operations  in  com- 
mercial dairy  barns  was  sufficient  to  appreciably  raise  the  bacterial 
content  of  the  milk  and  such  conditions  should  be  guarded  against. 

The  experiments  indicate  that  bacterial  contamination  of  milk  from 
11 


162 


CITY  MILK  SUPPLY 


the  air  of  stables  is  much  less  important  than  has  been  thought  and  that 
a  reasonable  amount  of  care  in  avoiding  extremely  dusty  operations 
during  milking  will  suffice  to  protect  the  milk  adequately. 

Thus  the  quantitative  microbial  pollution  of  milk  by  stable  air  is 
fairly  well  understood  but  there  is  little  known  about  the  relative  im- 
portance of  the  germs  of  different  groups  in  the  air-borne  contamina- 
tion that  does  occur.  Bacteria  yeasts  and  moulds  are  all  found  in  stable 
air.  Among  the  bacteria  certain  micrococci  are  common  and  so  are 


Courtesy  of  J.  O.  Jordan. 

FIG.  30. — New  England  barn  of  the  type  in  which  the  air  is  seriously  contaminated  in 

feeding  the  hay. 

organisms  of  the  B.  subtilis  group.  Bacteria  of  the  B.  coli-Bact.  lactis 
aerogenes  group  may  be  swept  into  the  air  with  particles  of  dung  and 
from  other  sources.  Disease  germs  are  uncommon  in  the  air  but  to 
some  extent  Bad.  tuberculosis  and  other  pathogens  may  circulate  in  the 
air  in  infected  stable  dust.  In  a  goat  stable,  if  there  are  animals  which 
have  been  imported  from  Mediterranean  countries,  the  dust  is  likely 
to  be  infected  with  M.  melitensis.  Mould  spores  are  common  in  stable 
air  but  yeast  is  less  so  than  are  either  bacteria  or  moulds. 

Contamination  from  Feeds. — Feeds  of  various  sorts  are  often  rich  in 
bacteria  that  become  attached  to  the  leaves  or  kernels  of  grain  of  the 


SANITARY  MILK  PRODUCTION  163 

growing  plants  or  are  derived  from  the  soil  or  else  from  human  sources 
in  the  course  of  garnering  or  manufacturing.  Organisms  of  the  B. 
subtilis  group,  of  the  butyric  acid  group,  and  of  the  B.  coli-Bact.  aerogenes 
group,  all  have  been  found  abundantly  in  feeds.  It  has  been  noted  that 
condensed  milk  is  sometimes  spoiled  by  gassy  fermentations  produced 
by  spore-bearing  organisms  and  that  this  trouble  is  most  likely  to  occur 
in  the  autumn  when  crops  are  being  put  into  the  barn  and  the  stable  air 
is  filled  with  dust. 

Contamination  from  Bedding. — Bedding  is  the  source  of  many  kinds 
of  bacteria  and  of  moulds,  among  the  former,  those  of  the  B.  coli-Bact. 
lactis  aerogenes,  the  B.  subtilis  and  the  butyric  acid  groups  may  be  men- 
tioned. Clean  bedding  such  as  shavings,  sawdust,  peat  moss,  cocoa 
shells,  etc.,  gives  little  trouble  but  dusty,  smutty  or  mouldy  bedding  and 
a  litter  of  fallen  leaves,  horse  manure  or  of  sand  all  are  likely  to  produce 
ill  effects  on  the  milk.  One  of  the  worst  litters  from  the  point  of  view  of 
bacterial  contamination  that  the  author  ever  had  to  deal  with  was  a 
coarse  hay  that  was  cut  on  a  meadow  subject  to  periodical  overflow  by 
a  muddy  river.  Brainerd,  at  the  Virginia  Agricultural  Experiment  Sta- 
tion, made  a  short  series  of  experiments  in  the  Station  stable  to  determine 
the  source  of  bacteria  in  the  milk  produced  there.  Among  other  things 
he  found  that  when  bright  clean  straw  was  used  as  a  litter  the  bacterial 
content  of  the  milk  could  be  decidedly  reduced  by  moistening  the  straw 
before  milking,  and  that  with  sawdust  for  a  litter  as  good  bacterial  results 
were  obtained  as  with  moistened  straw. 

Contamination  from  Dairy  Utensils. — Dairy  utensils  have  been 
pointed  out  by  several  bacteriologists  as  a  fertile  and  serious  source  of 
milk  contamination.  The  trouble  corner  about  in  this  way:  a  little  milk 
containing  bacteria  or  their  spores  is  left  adherent  to  the  vessels  in  the 
form  of  inconspicuous  drops,  or  an  in  visible 'film  or  ever  so  slightly  milky 
water  that  condenses  at  the  time  of  scalding  or  steaming.  These  microbes 
establish  themselves  on  the  utensils  and  may  multiply  on  them;  in  either 
case,  they  germinate  in  the  milk  that  is  next  put  in.  Hasty,  careless 
cleaning  is  partly  to  blame  for  this  sort  of  pollution  but  it  is  also  partly 
due  to  faulty  construction  of  the  utensils,  to  washing  being  done  in  the 
wrong  way  and  to  scalding  or  sterilizing  being  neglected. 

All  utensils  should  be  made  with  as  few  seams  as  possible  and  the 
necessary  ones  should  be  flushed  with  solder  so  that  there  will  be  no 
crevices  in  which  milk  can  accumulate  and  be  decomposed  by  bacteria. 
So  far  as  practicable,  utensils  that  are  inconvenient  to  clean  should  be 
discarded;  certain  covered  milk  pails  and  cream  separators  are  of  this 
sort. 

New  tinware  is  easily  kept  clean  but  that  which  is  rusted  and  that 
which  by  rough  usage  has  had  the  tin  plate  knocked  off  cannot  be  cleaned 
so  that  there  will  not  be  large  numbers  of  germs  in  the  spots  and  crannies 


164  CITY  MILK  SUPPLY 

where  rust  shows.  Badly  rusted  and  dented  tinware  is  properly 
confiscated  by  boards  of  health. 

The  trouble  that  the  cleaner  causes  is  in  part  due  to  his  carelessness 
and  in  part  to  his  doing  the  work  in  the  wrong  way.  Vigorous  prodding 
by  some  one  in  authority  is  the  only  cure  for  the  shiftless  washer.  Proper 
cleansing  of  milk  vessels  is  effected  by  first  rinsing  them  in  cold  or  luke- 
warm water  to  remove  the  milk  after  which  they  should  be  scrubbed  with 
a  brush  inside  and  out,  in  hot  water  and  washing  powder;  then  they  should 
be  rinsed  in  clean  hot  water.  If  the  cold  rinse  is  omitted  the  hot  water 
will  cause  some  constituents  of  the  milk  to  stick  tenaciously  to  the 
utensils. 

Sterilization  of  milk  utensils  is  generally  effected  by  heat.  The 
effectiveness  of  the  process  depends  on  the  degree  of  temperature  and 
the  length  of  time  it  is  applied.  The  use  of  water  at  less  than  boiling 
temperature  and  hurrying  the  work  unduly,  makes  the  process  a  farce. 
The  smaller  vessels  and  bottles  can  be  thoroughly  sterilized  by  boiling 
them.  The  breakage  of  glassware  need  not  be  excessive  if  the  bottles 
and  other  dishes  are  first  put  in  tepid  water  which  is  afterward  brought 
to  a  boil.  Care  should  be  taken  to  cool  the  glassware  slowly,  otherwise 
it  is  apt  to  become  brittle.  In  many  small  dairies  and  in  all  large  plants 
steam  is  available  for  sterilizing.  It  is  used  in  several  ways;  it  may  be 
turned  into  cold  water  to  raise  the  temperature,  or  in  the  form  of  stream- 
ing steam  it  may  be  played  from  a  hose  onto  apparatus,  or  ejected  from 
stationary  jets  into  cans  and  other  tinware  or  turned  into  chambers  of 
various  sorts  containing  utensils  to  be  sterilized.  Under  pressure,  steam 
is  most  effective  as  a  sterilizing  agent  and  in  large  milk  plants  there  are 
huge  sterilizing  ovens  for  employing  it  in  this  way.  There  is  no  question 
of  the  effectiveness  of  steam  for  sterilizing,  when  it  is  faithfully  and 
intelligently  used.  It  gives  a  sense  of  security  to  see  it  freely  employed 
for  this  purpose  in  a  milk  plant  or  factory,  but  this  feeling  is  often  unwar- 
ranted for  very  frequently  the  steam  is  not  applied  long  enough  to  the 
utensils  to  more  than  raise  the  temperature  to  the  point  where  bacterial 
multiplication  is  stimulated,  or  else  it  merely  loosens  the  milk  or  bacterial 
coating  adherent  to  the  utensils  so  that  the  next  milk  that  is  put  in  them 
is  heavily  contaminated.  Bacterial  tests  made  some  hours  after  cans 
have  been  steamed  often  show  how  imperfect  sterilization  has  been  and 
a  foul  odor  indicative  of  bacterial  decomposition  is  often  plainly  notice- 
able when  covers  are  removed  at  the  farm,  from  cans  washed  and  steamed 
at  the  city  milk  plant  or  creamery.  A  device  that  will  insure  the  exposure 
of  the  utensils  to  the  action  of  the  steam  jets  for  a  fixed  length  of  time  is 
needed.  While  with  autoclaves,  sterilizing  is  less  likely  to  fail,  the  danger 
still  exists  for  if  they  are  run  carelessly  the  pressure  required  to  sterilize 
may  not  be  reached. 

When  tinware  is  sterilized  by  streaming  steam  it  should  be  dried 


SANITARY  MILK  PRODUCTION 


165 


thoroughly;  in  large  plants  this  is  done  by  a  hot-air  blast.  If  one  is  not 
used,  unless  the  utensils  are  carefully  drained,  milky  puddles  from  the 
condensed  steam  collect  in  them  and  soon  support  rich  bacterial  growths. 
On  the  farm  after  scalding  or  boiling,  utensils  are  usually  wiped  with  a 
cloth;  it  should  either  be  new,  or  one  that  has  been  boiled  and  dried 
quickly.  Bacteria  multiply  in  cloths  so  long  as  they  are  wet,  and  the 
good  effect  of  boiling  utensils  is  often  entirely  destroyed  by  wiping  them 
afterward  with  a  cloth  that  supports  a  rich  growth  of  germs.  Sunlight 
has  a  strong  disinfecting  action  and  for  that  reason  it  is  good  to  sun  the 
tinware  on  a  rack  out  of  doors  in  a  place  free  from  dust  and  protected  from 
flies.  In  the  dairy,  the  utensils  should  be  kept  in  a  well-aired  place  free 
from  strong  odors  and  they  should  be  inverted  so  that  no  dirt  can  fall 
into  them. 

Prucha  of  the  University  of  Illinois  Station  has  for  some  time  been 
studying  the  microbial  contamination  of  milk  by  utensils.  He  has  given 
out  a  few  of  his  results;  a  brief  statement  of  them  is  found  in  Tables  47, 
48  and  49. 

TABLE   47. — THE   BARN  AS  A  SOURCE   OF   BACTERIAL   CONTAMINATION   OP   MILK 

(PRUCHA) 


Barn 

Number  of  samples 

Bacteria  per  cubic 
centimeter 

No    1,  very  clean 

525 

2,227 

No.  2,  less  clean  than  No.  1  .    . 

390 

1,073 

No.  3,  decidedly  dirty  

150 

6,604 

TABLE  48. — UTENSILS  AS  A  SOURCE  OF  BACTERIAL  CONTAMINATION  OF  MILK  (PRUCHA) 


Bacteria  per  cubic 
centimeter 


All  utensils  sterile 

Milk  leaving  barn 

Same  milk  bottled 

Only  bottles  sterile 

Increase  due  to  three  pails 

Increase  up  to  clarifier 

Increase  due  to  clarifier 

Increase  due  to  cooler 

Increase  due  to  bottler 

Total  increase  in  bottled  milk . . 


2,558 
3,875 

57,077 

15,353 

172,763 

19,841 

247,611 

515,200 


Table  47  shows  the  bacterial  content  acquired  by  the  milk  from  the 
udders  of  the  cows  and  the  various  barn  influences  to  which  it  was 
exposed  in  being  milked  into  a  sterile  pail. 

As  regards  Table  48  the  milk  was  brought  by  the  milkers  in  their 
pails  to  the  milk  room  in  the  barn  where  it  was  found  to  have  an  average 


166    •  CITY  MILK  SUPPLY 

TABLE   49. — CONTAMINATION  OF  PASTEURIZED   MILK  BY  THE  BOTTLING  MACHINE 

(PRUCHA) 


Bacteria  per  cubic 
centimeter 

Raw  milk 

Bottles  and  bottler  sterile 

36,860 

Pasteurized 

milk                     

1,030 

1st  bottle  o 

f  milk                                                          

923 

54th  bottle 

of  milk  

1,030 

1st  bottle 

Bottles  sterile,  bottler  only  washed 

107,500 

27th  bottle 

11,950 

54th  bottle 

4,170 

bacterial  content  of  2,558  per  cubic  centimeter.  In  the  milk  room,  the 
milk  was  poured  through  a  strainer  out  of  which  it  ran  through  about  20 
ft.  of  sanitary  pipe  to  a  clarifier  tank,  thence  through  the  clarifier,  thence 
over  an  open  tubular  cooler  into  cans  from  which  it  was  poured  into  a 
four-valve  bottler.  When  all  of  these  utensils  were  sterile  the  bottled 
milk  had  a  bacterial  count  of  but  3,875  per  cubic  centimeter  which  meant 
that  there  was  an  increase  in  bacteria  attributable  to  the  utensils  of  but 
about  1,300  bacteria  per  cubic  centimeter.  In  contrast  to  this  when  the 
utensils  through  which  the  milk  passed  were  carefully  washed  but  were 
not  sterilized,  the  milk  had  a  bacterial  count  of  about  half  a  million. 

Table  49  showing  the  test  of  the  bottler  in  a  sterile  and  in  an  insterile 
condition  with  pasteurized  milk.  In  a  sterile  condition  the  first  and 
fifty-fourth  bottles  had  the  same  bacterial  count  but  when  the  bottler 
was  merely  carefully  washed  previous  to  beginning  bottling,  the  milk  in 
the  first  bottles  filled  showed  a  higher  bacterial  count  than  the  raw  milk 
and  it  was  calculated  that  when  the  bottler  was  not  sterilized  it  added 
4  billion  bacteria  to  the  300  qt.  of  milk  bottled. 

The  results  of  this  extensive  investigation  are  convincing  evidence 
of  the  highly  important  part  that  milk  utensils  play  in  contaminating 
market  milk.  Milk  in  the  course  of  its  progress  from  the  farm  to  the 
consumer  is  thoughtlessly  poured  from  container  to  container  and  yet 
a  little  reflection  would  lead  one  to  conclude  that  milk  must  pick  up  dirt 
and  germs  from  unclean  and  insterile  vessels  of  all  sorts  with  which  it 
comes  into  contact.  Such  being  the  case,  the  pollution  derived  from 
utensils  becomes  impressive. 

Wherever  piping  is  used  to  conduct  milk  about  a  dairy,  it  should  be 
of  the  type  catalogued  as  "sanitary."  It  is  seamless  and  the  fittings 
make  a  smooth  joint.  Even  this  kind  is  difficult  to  clean.  It  should  be 
taken  apart  at  least  twice  a  day  and  when  not  in  constant  use  oftener, 
for  the  lengths  to  be  scrubbed  out  with  long  brushes  and  sterilized. 

Acid-forming  bacteria  are  the  principal  ones  that  get  into  milk  from 


SANITARY  MILK  PRODUCTION  167 

the  utensils  and  high  counts  of  acid-forming  colonies  are  likely  to  lead 
to  inquiries  as  to  the  care  given  the  dairy  utensils.  Hunziker  states  that 
very  common  sources  of  bacteria  of  the  butyric  acid  group,  that  are  so 
likely  to  spoil  condensed  milk,  are  cheese-cloth  strainers  and  utensils. 

Utensils  are  sometimes  seeded  with  bacteria  that  are  derived  from 
impure  waters  in  which  they  are  washed  and  occasionally  considerable 
loss  arises  from  these  germs  causing  ropy  milk  or  imparting  bad  flavors 
to  milk  and  butter.  Some  epidemics  have  been  attributed  to  the  wash- 
ing of  utensils  in  infected  water.  The  water  supply  of  the  dairy  is 
important. 

The  Water  Supply  of  the  Dairy  Farm. — A  dairy  farm  requires  an 
abundant,  supply  of  pure  water.  There  are  two  reasons  for  protecting 
it  from  contamination,  namely:  (1)  fecal  pollutions  may  infect  the 
water  with  bacteria  and  animal  parasites  that  cause  diseases  of  stock 
or  more  likely  of  man;  and  (2)  impure  water  may  carry  germs  of 
various  sorts  that  cause  ropy  or  ill-flavored  milk  or  that  impart  bad 
flavors  to  butter  and  other  manufactured  dairy  products.  Most  writers 
distinguish  between  polluted  or  contaminated  water  and  infected  water, 
the  first  and  second  terms  being  applied  to  waters  that  have  picked 
up  impurities  of  various  sorts  that  are  not  necessarily  harmful  to  health, 
but  the  third  term  is  restricted  to  waters  that  contain  the  specific  germs 
of  disease.  Water  that  is  open  to  contamination  is  so  to  infection. 
How  is  it  then  that  many  families  regularly  use  polluted  water  without 
apparent  ill  effects  except,  that  diarrheas  may  be  occasionally  attributed 
to  the  water?  The  answer  is  that  the  contaminating  filth  whether  it 
is  of  excremental  or  of  less  objectionable  origin  does  not  contain  the 
germs  of  disease.  But  families  often  do  suffer  from  minor  ills  for  which 
the  impure  water  is  responsible  and  they  live  in  constant  danger,  for 
at  any  time  infection  may  be  introduced  through  the  same  channels 
that  the  relatively  innocuous  filth  traverses.  Thus  a  privy  that  has  long 
leached  into  a  well  without  sickening  the  users  of  the  water  may  bring 
them  down  with  typhoid  fever  as  the  result  of  its  having  been  used  by  a 
typhoid  bacillus  carrier  or  by  one  afflicted  with  the  fever. 

Hitherto  farmers  have  paid  little  heed  to  the  protection  of  the  purity 
of  their  water  supplies.  For  this  there  are  two  principal  reasons,  the 
first  being  that  many  of  the  wells  were  built  before  our  present  knowledge 
of  the  causation  of  disease  was  current,  and  the  second  that  the  effect 
on  health  of  using  polluted  drinking  water  is  not  always  apparent.  The 
aged  grandfather  lives  on  despite  his  daily  dose  of  diluted  dejecta;  the 
infant  that  died  of  " bowel  complaint"  is  not  present  to, protest  the  old 
man's  scoffing  at  the  germ  theory.  Convenience  has  naturally  played 
a  determining  part  in  locating  the  farm  well.  The  result  is  that  regard- 
less of  conditions  that  obviously  threaten,  it  holds  its  place  midway 
between  the  kitchen  and  the  barn. 


168  CITY  MILK  SUPPLY 

The  percentage  of  farm  wells  that  are  polluted  probably  varies  con- 
siderably in  different  dairy  districts.  Kellerman  and  Beckwith  in  1906 
examined  the  wells  of  dairies  supplying  Washington,  B.C.,  and  found  16 
good,  15  fair,  17  suspicious  and  12,  or  20  per  cent.,  unfit  for  use.  The 
reports  of  the  health  officer  of  the  District  for  the  4  years  from  1905-06 
to  1908-09  show  that  the  wells  on  881  dairy  farms  were  tested  and  that 
519  were  good,  69  suspicious  and  293,  or  33.3  per  cent.,  were  condemned. 
The  location  of  these  wells  is  not  given  but  they  are  presumably  for  the 
most  part  in  Virginia,  Maryland  and  the  District  of  Columbia.  Keller- 
man and  Whittaker  in  their  investigation  of  the  farm  water  supplies  of 
Minnesota  tested  79  carefully  selected  and  typical  rural  water  supplies 
and  found  that  59  were  polluted,  usually  because  of  careless  or  ignorant 
management.  They  estimate  the  proportion  of  polluted  supplies  in 
rural  districts  at  35  per  cent.  Prescott  examined  the  water  supplies 
of  202  dairy  farms  situated  within  25  to  40  miles  of  Boston  and  found  14.4 
per  cent,  so  badly  polluted  as  to  be  unfit  for  use  as  drinking  water  or  for 
other  domestic  purposes. 

Wells  are  valuable  property  and  when  one  is  found  to  be  polluted  it 
should  be  saved  if  possible,  rather  than  condemned.  Sometimes  the 
relocation  of  a  sink  drain,  a  privy  or  a  hog  pen  or  the  addition  of  a  new 
curbing  or  cover  is  an  effective  cure  of  the  pollution. 

Prescott  suggests  the  following  form  for  use  in  inspecting  farm  water 
supplies. 

Water-supply  inspection 

Name  of  tenant Water  piped  to  barn 

No.  of  people  in  family Character  of  tank,  if  any 

Children,  servants  or  laborers Kind  of  pipe 

General  health  of  family General  character  of  soil 

Source  of  water,  well,  spring,  etc If  well,  when  last  cleaned 

Depth  of  well General  appearance   of  farm  surround- 

Distances  of  sources  from  house  drain         ings 

(a) Is  water  used  for  cooling  milk  or  food 

Distance  from  cesspool  or  privy  (6) Sample  taken  at 

Distance  from  .barnyard  (c) Analytical  data 

Surface  wash 20°C.  count 

Immediate  surroundings 37°C.  count 

Protection    against    contamination   from     Litmus  lactose  agar  count 

cattle,  manured  fields,  etc Acid  formers 

Covering,  if  any Presumptive  test,  dextrose  broth 

Date Presumptive  test,  lactose  bile 

Town  and  State B.  coli 

Water  piped  to  house Remarks 


The  quantity  of  water  needed  on  the  farm  as  estimated  (Trullinger) 
is  given  in  Table  50. 


SANITARY  MILK  PRODUCTION  169 

TABLE  50. — APPROXIMATE  QUANTITY  OF  WATER  REQUIRED  PER  DAY  ON  THE  FARM 

Gallons 

Each  member  of  family  for  all  purposes 25-40 

Each  cow 12.0 

Each  horse 10.0 

Each  hog 2.5 

Each  sheep 2.0 

This  makes  no  allowance  for  water  for  steam  making  or  for  washing  dairy  utensils 

Most  ground  waters  are  hard  because  the  water,  being  long  in  con- 
tact with  the  rocks  through  which  it  makes  its  way  and,  in  the  case  of  the 
deeper  waters,  being  under  pressure,  dissolves  mineral  substances  from 
the  earth.  Some  ground  waters  are  only  slightly  mineralized  while  others 
are  so  heavily  charged  with  mineral  substances  as  to  be  entirely  unfit 
for  use.  Hard  waters  increase  soap  consumption  and  also  the  cost  of 
operating  steam  boilers  for  they  deposit  hard  or  soft  scales  that  in- 
crease the  fuel  consumption  and  injure  the  boilers.  Some  waters  cause 
foaming,  while  others  corrode  boilers  and  sometimes  cause  them  to 
explode.  In  many  steam  plants,  boiler  compounds  and  corrective 
measures  of  various  sorts  are  applied  to  make  the  water  usable.  In 
many  industries  the  mineral  content  of  water  has  a  deleterious  effect 
on  the  product  manufactured.  At  the  South  Dakota  Station  the  effect 
of  alkali  water  in  making  butter  and  cheese  and  also  on  the  cow  and 
her  milk  was  studied,  but  no  unfavorable  results  were  observed  to  attend 
its  use. 

Contamination  of  Milk  by  Ice. — Ice  is  used  liberally  in  many  dairies; 
in  fact  in  summer  it  is  all  but  necessary.  Care  should  be  taken  to  have 
it  pure.  The  late  Thomas  M.  Drown  showed  that  ice  in  freezing  has 
a  decided  tendency  to  exclude  impurities,  but  he  found  this  action  to  be 
most  marked  in  the  layers  that  are  formed  by  the  slow  growth  of  the 
ice  downward,  because  the  surface  in  its  rapid  congealing  entangles 
suspended  matter,  particularly  if  the  water  is  stirred  up  by  the  wind. 
Moreover,  if  the  ice  is  frozen  after  surface  flooding,  which  is  frequently 
brought  about  intentionally  by  the  harvesters,  it  will  contain  all.  of  the 
impurities  of  the  water  so  added.  In  making  artificial  ice  in  the  ordinary 
way,  the  entire  body  of  water  is  frozen  and  all  the  impurities  are  concen- 
trated in  the  last  part  of  the  cake  to  freeze.  Hence  an  impure  water  is 
especially  undesirable  for  ice  manufacture.  Likewise,  when  shallow 
ponds  freeze  solid,  the  impurities  are  concentrated  in  the  bottom  ice. 
Sedgwick  and  Winslow  proved  that  typhoid  bacilli  perish  rapidly  in  ice, 
even  98  per  cent,  of  them  dying  in  2  weeks.  This  indicates  that  there 
is  little  reason  for  fearing  that  this  disease  may  be  introduced  into  the 
dairy  by  ice  and  the  fact  that  there  is  no  perfectly  clear  case  of  typhoid 
fever  having  infected  a  milk  supply  through  the  medium  of  ice  is  con- 
firmative of  this  view.  Artificial  ice,  being  often  used  without  storage, 


170  CITY  MILK  SUPPLY 

may  perhaps  be  somewhat  less  safe  than  natural  ice.  Despite  the  fact 
that  there  is  little  danger  to  be  apprehended  from  the  ice  supply  care 
should  be  taken  that  it  is  pure  for  while  infection  from  impure  ice  is 
not  likely,  it  is  possible. 

Human  Contamination  of  Milk. — Man  himself  is  an  important  source 
of  contamination  and  sometimes  of  infection  of  the  milk.  The  dis- 
charges of  the  mouth,  nose,  ears,  anus  and  urinary  bladder  are  most 
important.  The  operations  of  the  toilet  are  such  that  the  hands  are 
almost  inevitably  soiled  in  its  use,  consequently  employees  should  be 
instructed  to  wash  their  hands  thoroughly  before  leaving  the  closet. 
It  is  the  habit  of  man  to  be  constantly  fingering  his  mouth  and  picking 
his  nose  and  ears  consequently  the  hands  most  of  the  time  are  unclean. 
So,  it  is  important  that  milkers  and  others  should  wash  their  hands  care- 
fully before  beginning  work.  They  should  be  taught  there  is  an  invisible 
dirt  on  the  hands  which  is  likely  to  seriously  injure  the  product  and  that 
for  this  reason  it  is  for  the  interest  of  the  dairy  that  the  hands  should  be 
kept  away  from  the  milk  as  much  as  possible.  The  practice  of  milking 
with  wet  hands  is  to  be  condemned  as  one  that  is  sure  to  contaminate 
the  milk.  Milk  is  sometimes  polluted  and  possibly  infected  by  the  cough- 
ing of  one  handling  it.  Fine  drops  of  saliva  are  ejected  into  the  air  and 
fall  with  their  contaminated  germs  into  the  milk.  The  clothes  of  people 
working  about  milk  should  be  clean  because  if  they  are  dirty  they  are 
foul-smelling  and  so  may  impart  odor  to  the  milk  and  also  dirt  and  germs 
get  into  the  milk  from  the  clothes.  Certified  dairies  make  a  point  of  the 
milking  and  the  subsequent  handling  of  milk  being  done  by  employees 
dressed  in  clean  and  sometimes  in  sterile  clothes.  It  is  too  much  to 
expect  the  ordinary  dairyman  to  attempt  anything  of  the  sort  but  he 
can  conveniently,  and  without  increasing  the  expense  of  laundering,  have 
clean  overalls  and  jumper  for  milking  in,  that  he  can  use  for  ordinary 
farm  work  when  they  become  soiled. 

Contamination  of  Milk  by  Domestic  Animals  and  Vermin. — There 
is  some  danger  of  milk  being  contaminated  by  domestic  animals  and 
vermin.  There  are  dairies  where  cats  are  kept  to  catch  mice  and  rats 
and  at  milking  time  puss  gets  at  the  milk  if  she  can.  In  the  inferior 
class  of  dairies,  the  doors  of  the  milk  house  are  often  left  open  consequently 
hens  get  in,  and  their  droppings  as  well  as  those  of  mice  and  rats  fall 
into  any  utensils  that  are  carelessly  left  standing  mouth  upward.  Once 
in  a  great  while  it  is  reported  that  a  rat  has  been  found  drowned  in  a 
can  of  milk  that  has  been  left  uncovered  in  the  creamery  over  night.  , 

Contamination  of  Milk  by  Flies. — While  this  sort  of  contamination 
is  disgusting  it  is  not  of  common  enough  occurrence  to  make  it  very 
important  but  the  contamination  of  milk  by  flies  in  summer  is  constant 
and  serious.  Many  of  the  best  dairies  are  trying  to  cope  with  it.  Flies 
are  fond  of  milk  and  swarm  wherever  it  is  exposed,  consequently  in  the 


SANITARY  MILK  PRODUCTION  171 

barn  at  milking  time  they  are  at  the  pails,  cans  and  strainers,  and  in  the 
milk  house  they  hover  about  the  vats,  coolers,  separators,  bottlers,  etc., 
falling  into  the  milk  and  polluting  it  with  germs  washed  from  their  bodies. 
Moreover,  theylight  on  the  clean  glass  and  tinware,  soiling  it  with  their 
defecations  and  the  regurgitations  from  their  crops.  To  control  or 
even  to  minimize  the  pest  is  most  difficult.  There  is  usually  enough 
manure  and  straw  about  the  stables  for  flies  to  breed  in  myriads. 
Probably  it  helps  to  reduce  the  number  of  flies  to  keep  the  barns  swept, 
the  yards  clean  and  to  have  the  manure  removed  daily  or  at  least  at  weekly 
intervals.  The  use  of  large  fly  traps  such  as  the  Hodges  and  the  Minne- 
sota results  in  the  capture  of  many  of  the  insects  and  tends  to  reduce 
them  in  number.  Some  dairymen  try  to  keep  out  the  flies  by  darkening 
the  stable  and  leaving  a  small  open  window  for  the  flies  to  get  out,  the 
milking  being  done  by  artificial  light.  In  the  flyless  dairy  of  the  United 
States  Naval  Academy  at  Annapolis,  Md.,  the  stables  are  light  but  they 
are  very  carefully  screened.  Flies  are  brought  into  the  barn  on  the  cows; 
so  some  easy  way  of  brushing  the  insects  off  must  be  adopted.  One  in 
common  use  is  to  have  the  cows  come  in,  through  a  covered  passage  way 
from  which  gunny  sacks  are  hung  so  that  they  brush  the  cows'  backs. 
In  the  milk  house  and  in  city  milk  plants  careful  screening  combined 
with  the  use  of  fly  traps  and  sticky  fly  paper  is  the  best  way  to  keep  down 
the  flies.  The  use  of  poison  fly  paper  and  of  fly  poisons  of  various  sorts 
in  the  dairy  is  not  advisable  because  they  may  cause  accidents  and  be- 
cause the  poisoned  flies  drop  everywhere. 

Essentials  of  Clean  Milk  Production. — It  must  be  apparent  that  with 
so  many  sources  of  milk  pollution  deserving  attention,  it  is  a  difficult 
matter  to  reduce  dairy  sanitation  to  such  simple  terms  that  the  pre- 
cautions deemed  essential  will  seem  reasonable  to,  and  be  adopted  by, 
the  ordinary  dairyman.  Probably  most  authorities  would  agree  that 
wiping  the  cows'  udders,  milking  with  dry  hands,  the  use  of  the  small-top 
pail,  the  thorough  cleansing  and  sterilizing  of  utensils  and  the  cooling 
of  the  milk  to  below  50°F.  are  all  necessary  to  the  production  of  clean 
wholesome  milk. 

The  North  System. — C.  E.  North  has  evolved  a  system  which  at- 
temps  to  bring  the  number  of  things  to  be  done  by  the  dairyman,  in 
producing  clean  milk,  to  a  minimum  and  to  interest  him  in  the  production 
of  such  milk  by  paying  extra  for  it. 

The  North  system  is  in  operation  at  Homer,  N.  Y.,  at  Sparks,  Md., 
and  in  other  places.  Briefly  it  is  this.  In  the  dairy  district  is  established 
a  central  station  which  in  reality  is  a  milk  plant  for  the  community. 
It  is  well-lighted  and  ventilated,  has  waterproof  floors,  good  drainage 
and  water  supply.  It  is  equipped  with  apparatus  for  washing  and 
sterilizing  utensils,  for  cooling,  bottling  and  refrigerating  the  milk,  and 
with  a  laboratory.  There  all  the  farmers'  milking  pails  and  all  cans  are 


172  CITY  MILK  SUPPLY 

washed  and  cleaned,  sterilized  and  dried,  and  the  bottling  of  the  milk, 
the  bottle  washing  and  sterilizing  and  the  refrigeration  and  shipping  of 
the  milk  are  attended  to.  The  farmers  transact  their  business  with 
the  manager  of  the  central  plant,  bring  their  milk  there  and  receive  their 
cleaned  and  sterilized  milk  pails  and  cans  each  day  for  use  on  the  farm. 
At  the  dairy  farms,  milking  must  be  done  in  covered  pails  provided  by 
the  station,  which  in  transportation  to  the  farm  must  be  kept  clean. 
Milk  pails  and  cans  must  not  be  washed  or  sterilized  at  the  farm.  No 
strainers  and  no  utensils  other  than  those  provided  by  the  station  must 
be  used  and  all  milk  must  be  cooled  by  placing  it  in  40-qt.  cans  in  ice 
water.  The  superintendent  does  the  chemical  and  bacteriological  work 
and  posts  the  results  of  his  tests  of  the  farmer's  milk.  He  also  inspects 
the  dairy  farms  and  in  doing  so  helps  the  farmers  by  instructing  them 
on  simple  points  of  sanitation. 

Payment  for  the  milk  is  made  on  the  basis  of  cleanliness  as  indicated 
by  the  bacterial  counts  and  on  its  richness  as  shown  by  the  butterfat 
test.  Milk  of  a  low  bacterial  and  high  butterfat  test  brings  a  better 
price  than  milk  of  high  counts  and  low  test.  A  still  higher  price  is  payed 
for  milk  of  the  former  class  from  tuberculin-tested  cows. 

North  claims  to  have  been  very  successful  at  Homer  and  at  Sparks, 
in  interesting  the  farmers  and  in  getting  good  milk.  It  is  his  belief  that 
the  dairyman,  or  his  methods,  is  a  factor  of  90  per  cent,  in  the  production 
of  clean  milk  and  the  equipment  of  10  per  cent,  and  he  holds  that  dairy- 
men trained  in  sanitary  methods  can  be  transferred  from  their  own  dairy 
district  to  any  other  and  on  the  day  of  their  arrival  produce  clean  milk. 
This  theory  was  actually  tested  by  taking  10  dairymen  from  Oxford, 
Pa.,  where  they  were  in  the  habit  of  producing  clean  milk  to  Kelton, 
Pa.,  where  the  farmers  were  not  producing  such  milk  but  wished  to  pro- 
duce milk  of  "grade  A"  rating.  These  Oxford  dairymen  had  been  pro- 
ducing milk  having  a  bacterial  count  of  about  18,000  per  cubic  centimeter, 
and  the  Kelton  dairymen  milk  running  about  1,500,000  per  cubic  centi- 
meter. In  the  Kelton  dairies  the  10  Oxford  dairymen  on  the  day  of  the 
test  produced  milk  that  showed  an  average  test  of  9,300  per  cubic  centi- 
meter. The  barns,  cows,  and  surroundings  were  exactly  the  same  but 
the  Oxford  men  used  sterilized  cans  and  sterilized  small-top  pails  which 
the  Kelton  men  did  not.  These  cans  and  pails  undoubtedly  were  factors 
in  reducing  the  count.  Other  factors  were  that  the  Oxford  men  milked 
with  dry  hands,  kept  the  40-qt.  receiving  cans  out  of  the  dust,  avoided 
raising  a  dust  at  milking,  did  not  use  cloth  or  wire  gauze  strainers  and 
cooled  their  milk,  without  stirring  it,  by  setting  it  in  40-qt.  cans  in  tanks 
or  barrels  of  cool  water. 

From  this  experience  and  other  observations  North  concludes  that 
the  factors  of  primary  importance  in  producing  clean  milk  are: 


SANITARY  MILK  PRODUCTION  173 

1.  Milking  with  clean,  dry  hands  into  covered  pails. 

2.  Thorough  washing  and  sterilization  of  milk  pails,  and  milk  cans. 

3.  Cooling  the  milk  by  placing  it  in  cans  in  tanks  of  cold  water,  or  of  ice  water. 

4.  Regular  laboratory  testing  of  milk  for  bacteria  and  the  making  of  payments  on 
the  basis  of  laboratory  tests. 

Dairy-farm  Score  Cards. — That  the  conditions  under  which  milk  was 
produced  bore  an  important  relation  to  its  character  soon  became  the 
conviction  of  the  pioneers  in  improving  the  quality  of  milk  delivered 
in  our  cities;  consequently  the  dairy  inspectors  of  the  large  milk  companies 
and  of  boards  of  health  shortly  began  to  pay  particular  attention  to  the 
sanitary  conditions  of  dairy  farms  and  to  make  reports  to  their  employers 
thereon.  For  convenience  in  filing,  and  to  systematize  the  inspection 
Borden's  Milk  Co.,  the  Board  of  Health  of  the  Town  of  Montclair  and 
others  substituted  printed  forms  for  written  reports.  These  early  forms 
were  rather  cumbersome  and  did  not  convey  to  the  reader  at  a  glance  a 
clear  impression  of  whether  the  farm  was  commendable  or  not.  Con- 
fusion arose  from  the  many  details  reported  and  the  fact  that  their 
relative  importance  was  not  clearly  indicated.  The  forms  did  not  show 
the  producer  and  consumer  either  the  faults  that  should  be  corrected 
forthwith,  or  give  them  a  basis  for  rating  the  sanitary  condition  of  the 
farm. 

Something  better  than  the  forms  was  needed  and  this  was  provided 
by  W.  C.  Woodward,  health  officer  of  the  District  of  Columbia,  who  on 
Jan.  9,  1904,  brought  out  the  first  dairy  score  card.  The  principle  on 
which  such  cards  are  constructed  is  that  the  different  items  that  appear 
are  assigned  weights  according  to  what  the  originator  of  the  card  deems 
to  be  their  relative  importance.  Thus  out  of  a  total  of  100  points  allowed 
for  say,  32  items  on  a  score  card,  5  points  may  be  allowed  for  annual 
tuberculin  testing,  5  for  the  use  of  the  small-top  milking  pail,  1  for  clean 
milking  suits,  2  for  construction  of  the  milk  room,  etc.  So,  when  the 
deductions  for  all  the  various  differences  have  been  made  the  sum  of 
the  points  allowed  is  less  than  100  and  gives  a  general  idea  of  the  sani- 
tary condition  of  the  farm  is  obtained  from  the  total  score,  and  from  a 
detailed  consideration  of  the  cuts,  it  may  be  seen  just  where  the  sanitation 
is  poor  and  what  is  necessary  to  do  to  improve  it.  A  feature  of  Dr. 
Woodward's  card  was  the  provision  for  scoring  equipment  and  methods 
on  one  side  and  the  cattle  on  the  reverse  side. 

In  February,  1905,  R.  A.  Pearson  of  the  Cornell  University  Station, 
working  independently  and  without  knowledge  of  the  existence  of  the 
District  of  Columbia  card,  brought  out  a  card  different  but  in  many  ways 
similar  to  it.  Pearson's  ideas  were  evolved  from  practical  experience 
gained  at  the  Walker-Gordon  farm  at  Plainfield,  N.  J.  In  July,  1906, 
C.  B.  Lane,  then  of  the  Dairy  Division  of  the  U.  S.  Department  of  Agri- 


174  CITY  MILK  SUPPLY 

culture,  prepared  a  modified  form  of  card  in  the  hope  of  extending  the  use 
of  the  score-card  system  and  securing  more  thorough  inspection. 

The  official  Dairy  Instructors'  Association,  upon  its  organization  in 
1906,  appointed  a  score-card  committee  consisting  of  C.  B.  Lane,  R.  A. 
Pearson  and  J.  M.  Trueman  to  prepare  a  card  that  would  best  meet  the 
needs  of  and  be  generally  adopted  by  dairy  inspectors.  At  the  second 
meeting  of  the  Association  in  October,  1907,  the  committee  submitted 
a  card  which  it  was  voted  to  print  and  distribute  for  trial  and  criticism 
among  the  heads  of  the  dairy  departments  of  the  agricultural  colleges. 
At  the  third  meeting  of  the  Association  in  July,  1908,  the  committee 
submitted  a  card  that  was  constructed  in  the  light  of  the  criticism  received 
and  which  was  adopted  after  some  minor  changes  had  been  made  in  it. 
The  Committee  was  continued,  and  since,  from  time  to  time,  has  advised 
changes  in  the  card  that  have  been  adopted  by  the  Association.  The 
present  members  are  C.  B.  Lane,  W.  A.  Stocking,  Jr.,  I.  C.  Weld,  E. 
Kelly,  and  H.  A.  Harding. 

To  promote  uniformity  in  the  use  of  the  score-card  the  Dairy  Divi- 
sion of  the  U.  S.  Department  of  Agriculture  has  cooperated  with  the 
Association  in  perfecting  the  card,  a  member  of  its  staff  being  appointed 
to  the  Committee,  and  has  adopted  the  score  card  in  its  official  inspec- 
tion work.  Thus  the  card  is  prepared  by  the  Official  Dairy  Instructors' 
Association  and  has  the  indorsement  of  the  United  States  Government, 
which  backing  has  led  to  its  adoption  in  1914  by  over  200  cities,  25 
State  departments  and  50  educational  institutions.  It  has  been  sent 
to  every  city  in  the  United  States  having  a  population  of  over  50,000. 
However,  it  has  not  been  universally  adopted,  some  cities  for  one  reason 
or  another,  preferring  to  use  cards  of  their  own  devising.  While  this 
card  has  been  used  in  a  great  variety  of  conditions  it  is  recognized  that 
it  is  all  but  impossible  to  make  up  a  card  that  will  be  equally  well  adapted 
for  use  in  the  different  States  of  the  Union.  In  New  England  cows  are 
stabled  half  the  year,  in  Colorado,  a  quarter  and  in  Florida  and  southern 
California  not  at  all;  consequently  that  part  of  the  card  which  pertains 
to  barn  construction  and  the  housing  of  cattle  is  of  very  unequal 
importance  in  these  States.  So,  it  is  to  some  extent  with  other  items. 

The^card  which  is  prepared  by  the  Dairy  Instructors  Association  and 
which  is  used  by  the  Federal  government  has  come  to  be  known  as  the 
"official"  score  card.  It  is  reproduced  below. 


SANITARY  MILK  PRODUCTION 


175 


"OFFICIAL  SCORE  CARD" 
(Front) 


EQUIPMENT. 

SCORE, 

METHODS, 

SCORE, 

Perfect, 

Allowed. 

Perfect. 

Allowed, 

cows. 
Health 

6 

1 

2 
4 

cows. 
Clean 

8 
6 

Apparently  in  good  health  _  1 

(Free  from  visible  dirt,.  6.) 

BTABLES. 

Ole&nllneej  of  stables 

If  tested  with  tuberculin  within 
a  year  and  no  tuberculosis  is 
found,  or  if  tested  within  six 
months  and  all  reacting  ani- 
mals ramnvwl                                  5 

Floor  2 

5 
1 

(If  tested  within  a  year  and  react- 
ing animals  are  found  and  removed, 

Food  (clean  and  wholesome)  
Water  (clean  and  fresh) 

Walls  ....                                 .  l 

Ceilings  and  ledges  1 

Mangers  and  partitions  1 

Windows               ^                    1 

Stable  air  at  milking  time 

STABLES. 

Location  of  stable 

Freedom  from  dust  3 

Freedom  from  odors  2 

Cleanliness  of  bedding 

Barnyard 

2 
2 
3 
8 

9 

2 
2 

2 
5 

3 
2 

Well  drained                                  1 

Clean                                      "T 



Free   from   contaminating   sur- 
roundings                                  1 

Well  drained-                              1 

Removal  of  manure  daily  to  50  feet 
from  stable 

Construction  of  stable 

Tight,  sound  floor  and  proper 
gutter..                        .        __  3 

4 

MILK  BOOM  OB  MILK  HOUSE. 

Cleanliness  of  milir  room  

UTENSILS  AND  MILKING. 

Care  and  cleanliness  of  utensils 

Smooth,  tight  walls  and  ceiling..  1 
Proper  stall,  tie,  and  manger  1 
Provision  for  light:  Four  sq.  ft.  of 
glass  per  cow. 

(Three  sq.  ft.,  3;  2  Sq.  ft,,  2;  1  sq. 
ft.,  1.    Deduct  for  uneven  distribu- 
tion. 
Bedding... 

1 

Thoroughly  washed                     2 

Sterilized  in  steam  for  15  min- 
utes                                        3 

Ventilation  

7 

Provision  for  fresh  air,  control- 
lable flue  system  .                     3 

1 
1 

5 

1 
2 

1 

(Placed  over  steam  jet,  or  scalded 
with  boiling  water,  2.) 
Protected  from  contamination..  3 
Cleanliness  of  milking 

(Windows  hinged  at  bottom, 
1.5;     sliding     windows,     1; 
other  openings,  0.5.  ) 
Cubic  feet  of  space  per  cow,  500 

Clean,  dry  hands   "                     3 

Udders  washed  and  wiped  6 
(Udders  cleaned  with  moist  cloth, 
4;  cleaned  with  dry  cloth  or  brush 
at  least  15  minutes  before  milking, 

HANDLING  THE  MILK. 

Cleanliness  of  attendants  on  milk 
room  . 

(Less  than  500  ft.,  2;  less  than 
400ft.,  1;  less  than  300  ft.,  0.) 
Provision   for  controlling  tem- 
perature                                   1 

UTENSILS. 

Construction  and  condition  of  uten- 
sils.. 

Milk   removed   immediately   from 
stable  without  pouring  from  paiL. 
Cooled  immediately  after  milking 
each  cow  

Water  for  cleaning  . 

(Clean,  convenient,  and  abundant.) 
Small-top  milking  pail 

Milk  cooler                   

Cooled  below  50°  F 

Clean  milking  suits 

(51°  to  55°,  4;  56°  to  60",  2.) 
Stored  below  50°F  ... 

MILK  BOOM  OR  MILK  HOUSE. 

Location:  Free  from  contaminating 
surroundings     ,.                        ^, 

(51°  to  55°.  2;  56"  to  60°  1.) 
Transportation  below  50°  F 

• 

(51°"to  55°,  1.5;  56°  to  60°,  1.) 
(If  delivered  twice  a  day,  allow 
perfect  score  for  storage  and  trans- 
portation.) 

Total.    .                            . 

Construction  of  milk  room  -.  
Floor,  walls,  and  ceilings.^  1 

........ 

Light,  ventilation,  screens  1 
Separate  rooms  for  washing  utensils 
and  handling  milk 

Facilities  for  steam 

1 

(Hot  water,  0.5.) 
Total  

40 

60 



Equipment +  Methods =  Final  Score. 

NOTE  1.— If  any  exceptionally  filthy  condition  fa  found,  particularly  dirty  utensils,  the  total  score  may  be  fur- 
ther limited. 

NOTE  2.— If  the  water  is  exposed  to  dangerous  contamination,  or  there  is  evidence  of  the.presence  of  a  dan- 
gerous disease  in  animals  or  attendants,  the  score  shall  bo  0. 


176 


CITY  MILK  SUPPLY 

UNITED  STATES  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ANIMAL  INDUSTRY, 

DAIRY  DIVISION. 


SANITARY  INSPECTION  OF  DAIRY  FARMS. 


SCORE    OARD. 

Indorsed  by  the  Official  Dairy  Instructors'  Association. 

Owner  or  lessee  of  farm — 

P.  O.  address ..— State 

Total  number  of  cows ,_._.  Number  milking 

Gallons  of  milk  produced  daily . . 

Product  is  sold  by  producer  in    families,    hotels,    restaurants,    stores. 

to -  dealer. 

For  milk  supply  of r. . — - - 

Permit  No. Date  of  inspection — — ,  191 

REMARKS  : 


(Signed} 


Inspector. 


In  practice  the  score  card  has  served  several  purposes.  In  the  first 
place,  it  has  been  an  aid  to  inspectors  in  their  work,  for  on  filling  out  all 
its  items  they  could  be  sure  that  no  important  points  of  inspection  had 
been  overlooked  while  by  comparing  the  scores  the  relative  merits  of 
dairy  farms  could  be  judged;  also,  by  reflecting  on  the  mental  impressions 
made  by  the  farms  and  on  the  scores  a  check  on  both  could  be  had  so 
that  the  opinions  that  the  inspectors  had  of  the  several  dairies  in  their 
districts  was  less  likely  to  be  biased,  either  by  the  personal  impression 
made  by  the  dairyman  or  by  the  scores  themselves.  Besides,  the  cards 
served  as  guides  in  instructing  dairymen  on  the  importance  of  cleanliness 
in  handling  milk;  so  for  this,  and  other  reasons  it  is  advisable  to  leave  a 
carbon  copy  of  the  score  at  the  farm.  Moreover,  employers  of  several 
inspectors  could  check  the  work  of  their  staffs  by  transferring  their  men 
from  one  district  to  another  and  comparing  the  scores  turned  in.  Finally, 
the  score  cards  are  conveniently  filed  for  reference. 

It  should  be  understood  that  the  figures  obtained  by  scoring  are  not 
an  exact  mathematical  expression  of  the  sanitary  rating  of  the  farm. 


SANITARY  MILK  PRODUCTION  177 

On  the  contrary  they  are  greatly  influenced  by  the  system  of  cuts  em- 
ployed and  somewhat  also  by  the  mental  attitude  of  the  inspector.  Thus 
one  system  may  be  lenient,  in  that  it  makes  some  allowance  for  even  an 
attempt  to  approach  the  conditions  postulated  for  a  perfect  score,  whereas 
another  may  be  severe,  in  that  it  makes  no  allowances  of  the  sort.  For 
example,  if  6  points  are  allowed  for  the  item  of  cleanliness  of  the  stable, 
the  inspector  under  one  system  may  be  instructed  to  give  3  points  if  it 
is  half  clean  and  2  if  it  is  a  third  clean,  while  the  inspector  under  the  other 
system  may  have  orders  to  cut  6  points  if  the  stable  is  not  immaculately 
clean.  Likewise,  it  is  practically  impossible  for  the  inspector  at  dif- 
ferent times  to  score  the  same  farm  exactly  alike.  When  he  is  in  an 
amiable  mood  conditions  at  the  farm  are  likely  to  appear  better,  and  his 
cuts  are  possibly  a  trifle  less  than  when  he  is  scoring  under  the  spur  of  a 
rebuke  from  his  superior,  or  when  he  is  dealing  with  a  refractory  dairy- 
man. So  it  is  not  to  be  expected  that  the  scores  of  the  inspectors  operat- 
ing under  different  chiefs  will  be  strictly  comparable  or  that  those  of 
individual  inspectors  will  more  than  very  closely  approximate  the  truth. 
These  limitations  of  the  score  card  are  frankly  recognized  and  in  practice 
are  to  some  extent  guarded  against;  they  have  not  militated  against  its 
extensive  adoption  by  dairy  companies,  cities,  and  States  nor  roused 
opposition  among  farmers  to  its  use.  In  fact  the  score  card  has  made 
friends  rapidly  and  instead  of  inciting  strife  has  stirred  farmers  to  emulate 
one  another  in  securing  high  scores. 

The  score  card  is  a  means  of  stating  the  physical  conditions  of  the 
dairy.  It  was  designed  to  record  sanitary  conditions  on  the  farm  and 
to  secure  their  betterment  in  order  that  overcrowding  of  cows  in  the 
stables,  poor  ventilation  of  buildings  used  for  dairy  purposes,  filthy 
barns,  undrained  barnyards,  location  of  hog  pens  and  manure  heaps 
close  to  where  the  milk  was  handled,  the  use  of  poorly  constructed,  bat- 
tered or  worn  out  utensils  and  a  host  of  other  objectionable  conditions 
that  frequently  were  found  on  dairy  farms  and  that  from  time  to  time 
occasioned  publicity  campaigns  and  brought  dairying  into  disrepute, 
might  give  place  to  other  conditions  which  would  secure  the  approval 
of  the  public  and  establish  confidence  in  the  business.  While  it  was 
believed  that  some  of  these  things  in  some  degree  affected  the  quality 
of  the  milk  it  was  recognized  that  others  did  not.  The  score  card  at- 
tempted to  make  sure  that  the  environment  and  especially  the  methods 
of  milk  production  were  clean  and  comparable  with  those  that  attend  the 
production  of  other  foods,  rather  than  to  estimate  closely  the  quality 
of  milk  produced  on  any  particular  farm.  It  has  been  very  successful 
in  bringing  about  reforms  along  the  former  lines;  to  the  latter  purpose 
it  was  never  intended  to  be  applied.  No  doubt  in  the  main  the  dairies 
that  receive  high  scores  produce  better  milk  than  those  with  low  ones. 

Thus  the  committee  on  farm  sanitation  of  the  International  Association 
12 


178 


CITY  MILK  SUPPLY 


of  Dairy  and  Milk  Inspectors  instances  the  results  obtained  in  an  Eastern 
city  of  about  100,000  population  where  a  comparison  of  1,392  bacterial 
counts  from  484  dairies  during  the  5  years  1910,  1911,  1912,  1913  and 
1914  showed  that: 

47  dairies  scoring  over  80  gave  an  average  count  of  25,000  bacteria  per  c.c. 

46  dairies  scoring  70  to  80  gave  an  average  count  of  98,000  bacteria  per  c.c. 
334  dairies  scoring  61  to  70  gave  an  average  count  of  352,000  bacteria  per  c.c. 
711  dairies  scoring  50  to  61  gave  an  average  count  of  470,000  bacteria  per  c.c. 
254  dairies  scoring  under  50  gave  an  average  count  of  566,000  bacteria  per  c.c. 

But  results  do  not  always  have  this  trend.  High-scoring  dairies  often 
yield  milk  of  high  bacterial  count,  and  that  low-scoring  dairies  must 
necessarily  yield  high  counts  is  untrue. 

Brainerd  and  Mallory,  in  1911  studied  the  relation  between  the  scor- 
ings of  54  dairies  on  the  card  in  use  in  Richmond,  Va.,  and  the  bacterial 
counts  obtained  on  milk  sampled  at  milking  time  at  these  same  dairies 
and  plated  from  1  to  3  hr.  thereafter.  The  results  appear  in  Table  51. 

TABLE   51. — RELATION   BETWEEN  DAIRY  FARM    SCORES  AND  BACTERIAL   COUNTS 

(BRAINERD  AND  MALLORY) 


Score 

Number  of  dairies 

Number  of  counts 

Average  number  of 
bacteria  per  cubic 
centimeter 

67-70 

1 

4 

8,062 

70-73 

2 

7 

61,838 

73-76 

2 

19 

35,195 

76-79 

12 

35 

31,378 

79-82 

11 

40 

36,468 

82-85 

11 

39 

33,745 

85-88 

5 

18 

38,814 

88-91 

4 

12 

21,095 

91-94 

2 

7 

18,799 

94-97 

1 

4 

19,769 

Total 

54 

185 

From  these  experiments  the  authors  concluded  that  it  is  possible 
to  produce  good  milk  under  conditions  which  would  give  a  score  below 
any  effective  standard  which  might  be  established  and  that  it  is  not 
logical  to  condemn  milk  by  a  standard  that  bears  no  fixed  relation  to  its 
purity  or  sanitary  properties.  They  held  the  chief  defect  of  the  score 
card  to  be  that,  as  a  measure  of  the  sanitary  properties  of  milk,  none  of 
the  points  scored  have  a  permanent  value  under  all  conditions  and  it  is 
questionable  whether  they  have  a  definite  value  under  any  given  set 
of  conditions.  However,  they  recognized  the  score  card  to  be  of  the 
greatest  influence  in  improving  the  quality  of  milk  and  advocated  its 
use  until  some  better  method  should  be  developed.  They  suggested 


SANITARY  MILK  PRODUCTION  179 

giving  the  bacterial  count  a  fixed  value  in  the  score  card,  perhaps  to 
half  the  score. 

Brew  of  the  New  York  Station  has  recently  compared  the  bacterial 
content  of  milk  produced  in  34  dairies  scored  by  three  different  cards, 
namely,  the  "official,"  the  Cornell,  and  the  New  York  City,  and  found 
no  correlation  whatever  between  scores  and  the  counts.  He  states  that 
the  reason  for  the  discrepancy  cannot  be  certainly  given  but  that  the 
most  apparent  reason  is  that  a  large  number  of  items  included  on  the 
score  card  have  little  relation  to  the  number  of  bacteria  in  the  milk. 
He  says  that  in  the  district  studied,  it  was  not  true  that  low-scoring 
dairies  were  necessarily  insanitary  and  filthy  because  low-scoring  dairies 
were  found  that  compared  favorably  in  point  of  cleanliness  with  high- 
scoring  ones. 

In  spite  of  the  fact  that  the  score  card  is  not  intended  to  distinguish 
the  quality  of  milk,  there  has  gradually  grown  up  a  tendency  to  apply 
it  to  this  very  purpose,  and  of  late  there  has  developed  a  well-defined 
movement  to  convert  it  from  its  original  use  and  make  it  a  standard  of 
marketing. 

The  growth  of  the  desire  for  such  a  change  has  been  slow.  Its  origin 
may  be  traced  to  the  policy  of  boards  of  health  requiring  that  dairies 
should  attain  a  certain  minimum  score  in  order  for  the  milk  therefrom 
to  be  admitted  for  sale  within  their  jurisdiction  and  in  their  publishing 
the  scores.  Under  such  conditions  the  consumers  became  interested  in 
the  scores  and  very  generally  made  the  assumption  that  the  dairies  with 
the  highest  scores  had  the  best  milk.  The  fact  that  certain  of  the  large 
milk  companies  of  Chicago  paid  a  premium  for  milk  from  dairies  scoring 
65  or  more  tended  to  foster  the  same  idea  and  the  action  of  the  Public 
Health  Council  of  the  State  of  New  York  allowing  health  officials  to 
grade  milk  either  on  the  bacterial  counts  or  on  dairy  scores  alone,  will 
well-nigh  convince  the  milk-consuming  public  that  dairy  scores  are  an 
indication  of  milk  quality. 

Future  of  the  Score  Card. — With  the  understanding  that  the  effect 
of  the  cow  stable  and  its  surroundings  is  of  less  importance  than  other 
factors  on  the  quality  of  milk  there  has  developed  a  tendency  to  lay  less 
emphasis  on  dairy  inspection  and  more  to  judge  the  fitness  of  milk  for 
public  consumption  on  quality  alone.  In  fact,  the  question  is  raised 
whether  a  satisfactory  milk  supply  is  best  and  most  economically  secured 
by  inspection  or  laboratory  control.  Hitherto,  the  majority  of  cities 
have  relied  on  the  former  method,  but  since  the  grading  of  milk  has  been 
undertaken  there  has  been  a  decided  swing  toward  bacteriological  and 
chemical  examinations.  The  score  card  has  improved  the  environment 
in  which  the  dairyman  works,  has  educated  him  along  sanitary  lines,  and 
has  stimulated  him  to  take  pride  in  his  products  so  that  it  seems  intrinsi- 
cally sound  and  desirable  to  retain,  but  those  who  have  given  the  matter 


180  CITY  MILK  SUPPLY 

most  study  are  convinced  that  the  card  will  have  to  be  remade  so  that 
the  points  that  go  to  make  up  the  score  will  be  given  for  those  things 
that  are  known  to  affect  milk  quality.  It  was  to  so  modify  the  score 
card  that  the  studies  of  Harding  and  his  collaborators  on  barn  conditions 
were  undertaken  and  others  have  been  working  with  this  object  in  view. 

North  in  a  forthcoming  article  in  the  American  Journal  of  Public 
Health  proposes  a  card  that  is  based  on  the  study  of  various  score  cards, 
and  on  data  that  he  has  accumulated.  He  believes  that  the  great  factors 
in  producing  good  milk  are  proper  milking,  cooling,  and  sterilizing. 
The  things  that  have  an  important  effect  on  the  score  he  tabulates  thus : 


1.  Temperature:  Per  Cent. 

(a)  Winter  or  summer  weather  may  reduce  bacteria 90 

(6)  Ice  or  spring  water  for  cooling  may  reduce  bacteria ....  90 

(c)  Morning's  milk  or  night's  milk  may  reduce  bacteria ....  60 

2.  Covered  milk  pails  may  reduce  bacteria 90 

3.  Sanitation  (minus  cooling)  may  reduce  bacteria 87 

4.  Sterilization  of  utensils  may  reduce  bacteria 99 

5.  Type  of  producer  at  shipping  stations  may  reduce  bacteria  . .  84 

6.  The  human  factor  may  reduce  bacteria 99 . 99 

7.  The  cow  stable  and  surroundings  may  reduce  bacteria less  than  1 


North  separates  the  item  of  the  best  score  cards  into  those  of  primary 
and  those  of  secondary  importance  in  strict  accordance  with  the  degree 
in  which  they  affect  the  number  of  bacteria  in  the  milk  which  makes  the 
number  of  items  of  primary  importance  very  few  and  those  of  secondary 
many.  He  retains  the  vertical  division  of  the  card  into  equipment  and 
methods,  but  he  divides  it  also  by  a  horizontal  line  in  such  a  way  that  above 
it  is  a  list  of  equipment  and  methods  of  primary  importance,  and  below 
it  one  of  equipment  and  methods  of  secondary  importance.  The  things 
of  primary  importance  affect  the  decency  of  the  milk  and  those  of  second- 
ary, the  decency  of  the  dairy.  The  card  allows  100  points,  of  which  30 
are  for  primary  equipment,  60  for  primary  methods,  3.30  for  secondary 
equipment,  and  6.70  for  secondary  methods.  The  card  may  be  sum- 
marized as  shown  on  page  181. 

Whether  this  card  which  North  has  proposed  will  be  adopted  in  some 
form  or  not  cannot  be  predicted  but  even  in  the  skeleton  form  that  it  is 
given  here  it  serves  to  bring  out  how  differently  many  today  regard 
dairy  scoring  from  the  way  it  was  worked  out  in  the  "official"  card. 
It  is  the  author's  opinion  that  the  new  way  will  prevail  as  soon  as 
enough  data  has  been  collected  from  various  sources  to  give  a  sound 
basis  for  revision.  The  change  will  be  radical  and  it  therefore  de- 
mands thoughtful  consideration  by  all  concerned,  the  medical  profession, 
health  officers,  milk  companies  and  the  dairymen  themselves. 


SANITARY  MILK  PRODUCTION 


181 


SUMMARY  OF  THE  NORTH  SCORE  CARD 


Primary  Equipment 
Milking : 

Size,  condition  and  character  of  pails, 
cans  and  lids. 

Strainers  of  cotton  or  cheese-cloth  and 
held  in  place  by  a  good  sanitary  holder. 

No  metal  strainers  allowed. 
Cooling : 

Ice  supply. 

Water  sypply. 

Cooling  tank. 

Smooth  metal  stirring  rods. 
Sterilizing: 

Boiling  water  or  steam. 

Alkali  wash  powder. 

Scrubbing  brushes  used. 


Primary  Methods 
Milking : 

Udder  clean  before  milking. 

Milker's  hands  clean  before  milking. 

Small  mouth  milk  pails  in  use. 

Milk   strained   in   a    clear   atmosphere 

through  cotton  or  fine  cheese-cloth. 
Cooling : 

Milk  chilled  in  ice  water  to  50°F. 

Milk  chilled  in  running  water  to  55°F. 

Milk  chilled  in  standing  water  to  60°F. 

Sterilizing : 

Utensils  rinsed  in  clear  cold  water  right 

after  using. 
Scrubbed  with  brushes  in  alkali  powder 

and  rinsed. 

Sterilized  in  boiling  water  or  steam. 
Strainers  washed  in  alkali  solution  and 

boiled. 


Secondary  Equipment1 
Cow  Stable: 

Location  and  construction. 

Air  and  ventilation. 

Light. 
Milk  House: 

Location  and  construction. 
Privy: 

Location,  construction  and  screening. 


Secondary  Methods1 
Cow  Stable: 

Care,  free  from  dirt,  dust  and  odor. 
Cow  Yard: 

Well  drained. 
Manure: 

Distance  removed. 
Milk  House: 

Cleanliness,    freedom    from    flies     and 

rubbish. 
Employees : 

Conditions  of  clothing. 
Cow  feed: 

Condition  and  quality. 
Privy : 

Condition  and  disposal  of  contents. 


1  The  primary  equipment  and  methods  are  scored  in  whole  numbers,  the  secondary 
in  decimals.  Under  secondary  equipment  and  methods  only  outline  headings  are 
given;  the  card  is  very  detailed. 

Dirty  Dairies. — In  this  chapter  there  has  been  no  attempt  to  portray 
the  evils  of  dirty  dairying.  Within  the  memory  of  men  now  living  the 
milk  business  has  been  raised  from  a  primitive  trade  to  the  dignity  of  a 
recognized  industry.  When  the  evolution  commenced,  modern  sanita- 
tion itself  was  a  new  thing  and  its  application  to  dairying  an  experi- 
ment. It  was  soon  found  that  the  dairy  business  had  every  need  of  the 
new  science.  Almost  inconceivably  dirty  cows  and  filthy  barns,  miry 
barnyards,  menacing  privies,  impure  wells  and  cisterns,  and  unclean 


182  CITY  MILK  SUPPLY 

utensils  were  part  and  parcel  of  the  milk  trade  of  every  city.  Clean-up 
campaigns  were  the  order  of  the  day  and  the  disgusting  conditions  that 
were  often  disclosed  were  all  but  unbelievable.  The  medical  profession, 
working  largely  through  boards  of  health,  was  chiefly  responsible  for  the 
operation  that  cut  the  dirt  out  of  the  milk  business,  for  speaking  by  and 
large,  the  day  of  dirty  dairying  is  over.  It  still  persists  in  some  cities 
where  milk  companies  and  milk  inspectors  are  mixed  up  in  politics,  it 
undoubtedly  persists  in  communities  too  small  or  too  niggardly  to  pay 
for  inspection,  and  it  flourishes  in  granger  towns  where  business  men  feel 
that  the  farmer's  trade  is  so  important  that  they  had  rather  drink  dirty 
milk  than  disturb  business  by  a  clean-milk  campaign,  but  in  general  both 
milk  producers  and  milk  consumers  are  done  with  it,  and  its  nauseating 
details  have  been  so  often  blazoned  forth  that  it  seems  unnecessary  to 
say  more  about  it.  However,  because  of  the  importance  that  they  once 
had  and  because  of  the  acrimonious  campaigns  that  have  been  waged 
against  them  in  New  York,  Cincinnati,  Louisville,  and  other  American 
cities,  it  seems  well  to  say  a  little  about  "slop"  or  "swill"  dairies. 

Slop  Dairies. — They  were  so-called  because  the  cows  were  fed  on  the 
slop  or  refuse  from  distilleries.  As  early  as  1848,  a  committee  of  the 
New  York  Academy  of  Medicine  investigated  and  made  a  report  on  the 
slop  dairies  that  supplied  the  city.  This  action  was  taken  because  of 
the  oral  and  written  statements  made  by  physicians,  testifying  to  the 
evil  effect  of  such  milk  on  children  and  to  the  improvement  that  took 
place  in  their  condition  when  the  use  of  such  milk  was  discontinued. 

The  committee  stated  that  in  1842,  the  daily  milk  supply  of  the  city 
was  15,000  gal.  but  at  the  time  of  the  investigation  had  greatly  increased 
and  that  some  of  the  milk  was  brought  long  distances  by  steam,  the 
principal  source  of  supply  being: 

1.  Milk  from  grass-fed  cows,  as  from  Orange  County,  for  example,  that  was 
brought  by  steam. 

2.  Milk  from  cows  fed  partially  on  distillery  slop  and  that  was  brought  to  the  city 
by  steam  as  from  Newburg,  for  example. 

3.  Milk  from  cows  fed  partially  on  distillery  slop  in  the  neighborhood  of  the  city,  as 
at  Brooklyn,  Wallabout,  Bloomingdale,  etc. 

4.  Milk  produced  in  the  city  or  on  its  outskirts  from  cows  fed  solely  on  distillery 
slop,  as  on  Long  Island,  at  16th  and  42d  Streets. 

The  cow  sheds  at  Johnson's  distillery,  16th  and  10th  Avenue,  are 
described  in  detail.  At  this  particular  plant  the  cows  were  cleaned  but 
this  was  exceptional  and  the  filth  in  most  sheds  was  augean.  The  num- 
ber of  cows  at  Johnson's  ranged  between  2,000  and  4,000.  Several  thou- 
sand were  kept  confined  in  a  small  space  and  deprived  of  exercise.  Some 
hundreds  were  under  one  roof  but  a  few  feet  above  their  heads,  the  space 
being  heated  to  suffocation  by  the  sun,  by  steaming  slops  and  by  the 
breath  and  body  exhalations  of  the  cows.  No  litter  was  provided  and 


SANITARY  MILK  PRODUCTION 


183 


the  air  was  vitiated  by  the  constantly  flowing  urine.  The  animals  were 
brought  to  the  city  soon  after  calving.  At  first  they  refused  the  slop 
but  afterward  became  fond  of  it.  Often  they  became  sick  and  many 
died  soon  after  arrival.  Sore  foot,  in  several  cases  due  to  a  fungus 
growth  and  accompanied  by  carious  bones  and  a  discharge  of  pus,  was 
one  of  the  diseases.  Caries  of  the  teeth  was  common  in  cows  that  had 
been  fed  slop  for  6  months  and  in  time  the  teeth  loosened  and  fell  out. 

Later,  Frank  Leslie 's  Weekly  made  its  famous  onslaught  on  the  swill 
dairies.  This  was  known  as  the  short  or  stump-tail  cow  campaign  for 
the  cows  were  represented  as  suffering  from  a  disease  that  caused  part 
of  the  tail  to  drop  off.  The  expose  was  based  on  a  report  made  to  the 
Brooklyn  common  council  in  1857  by  a  committee  of  11  appointed  in 
response  to  a  petition  of  John  T.  Hildreth  et  al.  for  the  investigation  of 
cow  stables.  The  series  of  articles  in  Leslie's  began  on  May  8,  1858, 
and  ran  over  several  months.  They  are  profusely  illustrated  with 
drawings  and  cartoons  by  Nast  and  other  artists  and  depict  the  evils  of 


Courtesy  of  W.  E.  Miller. 

FIG.  31. — Method  of  conveying  slop  at  a  Cincinnati  swill  dairy.     Such  dairies  are  now 
entirely  eliminated  by  the  Pure  Food  Division-of  the  Cincinnati  Board  of  Health. 

the  swill  dairies  very  fully  and  clearly.  Undoubtedly  the  expose  is  one 
of  the  severest  arraignments  of  any  business  ever  published.  It  served 
a  useful  purpose  in  its  day,  is  an  instructive  record  of  bygone  conditions 
and  is  interesting  as  one  of  the  very  first  instances  of  pitiless  publicity 
being  used  to  compel  improvement  in  the  production  of  food  and  in 
general  sanitation.  The  incident  is  utilized  in  Ford's  novel,  "The  Hon. 
Peter  Sterling." 

Since  then,  many  States,  including  Pennsylvania,  Illinois,  Kentucky 
and  Indiana  have  prohibited  the  sale  within  their  borders  of  milk  from 
slop-fed  cows. 

In  1906-1908,  largely  under  the  leadership  of  0.  P.  Geier,  a  vigorous 
campaign  was  waged  against  the  slop  dairies  of  Cincinnati.  Of  conditions 
there  C.  B.  Lane  says: 

"I  visited  the  swill  dairies  supplying  milk  to  the  City  of  Cincinnati  and  found 


184  CITY  MILK  SUPPLY 

filth  and  insanitary  conditions  almost  indescribable  by  words  commonly  found 
in  the  dictionary. 

"This  condition  is  due  in  a  large  measure  to  a  swill  diet  which  causes  diarrhea 
and  keeps  the  platform  saturated  with  manure  mingled  with  swill.  Many  of 
the  cows  were  in  an  emaciated  condition,  some  were  coughing  and  looked  sick 
and  one  was  seen  dead  just  outside  the  stable.  The  cows  never  go  out  for  exer- 
cise, at  least  in  winter,  and  are  tied  up  in  small,  cramped,  slippery  stalls,  to  drink 
the  nauseating  sour  swill  and  breathe  the  close,  stench-laden  air  for  months  until 
they  are  sent  to  the  shambles.  These  herds  would  furnish  a  profitable  field  for 
investigation  by  the  Humane  Society  as  the  treatment  accorded  the  animals  is 
cruel  in  extreme. 

"  Invariably  the  stables  were  filled  with  steam  rising  from  the  swill,  which 
condensed  on  the  ceiling  and  continually  dropped  or  ran  down  the  walls.  No 
attempt  was  made  to  ventilate  the  stables — in  fact  the  windows  were  generally 
nailed  down  and  all  possible  openings  covered  with  boards. 

"Milk  rooms  were  generally  connected  directly  with  the  stable  and  were  just 
as  filthy  and  dirty.  There  was  no  provision  for  properly  cleaning  the  cans  and 
a  considerable  quantity  of  dirty  water  was  frequently  found  at  the  bottom  of 
them." 

One  of  the  arguments  used  in  the  campaign  against  these  dairies  was 
that  they  discouraged  legitimate  dairying,  it  being  impossible  for  dairy 
farmers  to  maintain  herds  fed  in  the  normal  way  in  the  face  of  competition 
from  slop-fed  herds.  The  fight  against  these  dairies  was  ultimately 
won,  it  having  been  found  after  2  years'  attempt  by  the  health  department, 
that  regulation  was  a  failure. 

It  should  be  understood  that  distillery  slop  can  be  fed  under  such 
conditions  as  to  produce  wholesome  milk.  The  chances  are  very  great 
that  it  will  not  be  fed  in  this  way.  Henry  says  that: 

"Distillery  slop  is  a  watery  attenuated  food  substance.  Being  produced  in 
great  quantities  it  must  be  gotten  out  of  the  way  quickly  and  it  is  usually  pumped 
into  feeding  sheds  and  there  distributed  in  troughs  to  animals  which  stand  and 
drink  it.  The  great  quantities  drunk  cause  the  passage  of  enormous  amounts 
of  water  through  the  kidneys.  Unless  the  greatest  precautions  are  taken,  the 
liquid  leaks  and  spills  everywhere  and  the  urine  distributes  itself  likewise.  Often 
the  animals  have  little  hay  and  other  food.  They  are  overfed  on  this  one  product 
because  it  must  be  quickly  and  continuously  disposed  of.  Good  flesh  in  steers 
or  good  milk  from  cows  can  hardly  be  produced  under  such  conditions." 

The  practical  results  of  the  campaigns  against  slop  dairies  have  been 
two,  namely:  (1)  they  have  been  largely  wiped  out  with  consequent 
improvement  of  the  city  milk  supply;  and  (2)  the  distilleries  have  in- 
stalled plants  for  evaporating  and  drying  the  slop  so  that  they  are  now 
recovering  and  selling  a  valuable  cattle  feed. 

The  Cost  of  Milk  Production. — The  several  elements  of  production, 
namely:  the  raising  of  proper  crops,  the  oversight  of  labor,  the  erection 
and  maintenance  of  barns  and  other  buildings,  the  formation  and  im- 


SANITARY  MILK  PRODUCTION  185 

provement  of  the  herd,  its  feeding  and  care,  the  sanitation  of  the  farm 
and  the  protection  of  milk  from  pollution,  all  must  be  competently 
handled  by  the  dairy  farmer  but  in  addition  to  the  ability  to  cope  with 
these  problems,  to  achieve  success  he  must  have  business  ability.  It 
must  be  evident  that  the  lax  conduct  of  any  one  of  these  phases  of  dairy- 
ing is  likely  to  raise  the  cost  of  production  and  that  the  prosperity  of  the 
dairyman,  the  success  of  the  city  milk  dealer  and  the  weight  of  the  burden 
that  falls  on  milk  consumers,  who  in  reality  support  the  entire  dairy 
business,  depend  in  large  measure  on  the  economical  and  efficient 
management  of  the  dairy  farm.  It  is  only  of  recent  years  that  farm 
accounting  has  been  so  systematized  that  fairly  accurate  production 
costs  can  be  calculated.  In  particular  the  cost  of  milk  production 
has  only  been  approximated.  However,  of  late  several  computations 
have  appeared  that  are  illuminating.  The  problem  is  difficult,  for  condi- 
tions on  the  farms  vary  much,  and  neither  horses  nor  men  are  constantly 
employed  in  labor  that  can  be  properly  charged  to  milk  production. 
Then  in  making  a  statement  of  costs  there  is  justifiable  difference  of 
opinion  as  to  whether  certain  costs  shall  be  excluded  or  not,  and  if  they 
are  included  as  to  how  they  shall  be  grouped.  The  costs  of  milk  pro- 
duction fall  under  three  main  heads,  namely:  feed,  labor  and  fixed 
charges.  Labor  is  a  fixed  charge  but  it  is  so  distinct  from  the  other 
items  listed  thereunder  that  its  separation  seems  warranted.  There 
are  presented  in  Table  52,  estimates  of  the  cost  of  milk  production  in 
nine  of  the  States.  It  will  be  observed  that  the  items  that  enter  into  the 
calculations  of  fixed  costs  are  not  the  same  in  the  divers  estimates,  but 
the  variation  is  perhaps  more  apparent  than  real,  for  the  item  " sundries" 
is  an  inclusive  one.  In  these  studies  no  allowance  has  been  made  for 
skim-milk  which  would  be  necessary  if  the  dairying  was  of  a  class  wherein 
much  remained  on  the  farm  which  is  not"  the  case  in  dairies  supplying 
the  city  milk  trade.  The  cost  of  feed  in  every  instance  is  50  per  cent,  or 
more,  of  the  total  cost,  the  labor  item  varies  from  20  to  30  per  cent, 
thereof.  Caution  is  needed  in  making  comparisons  between  the  different 
estimates  for  the  cost  of  production  varies  not  only  in  different  States 
but  in  different  parts  of  the  same  State.  However,  it  is  noticeable  that 
in  the  New  England  States  and  New  Jersey  the  feed  costs  are  higher  than 
elsewhere.  In  these  States  and  in  Maryland  the  cost  of  a  quart  of  milk 
is  between  4.5  and  5  cts.  In  the  States  of  the  Middle  West  the  cost  of 
a  quart  of  milk  is  from  2  to  2.5  cts.  The  figures  for  the  particular  county 
in  New  York  that  was  studied  are  comparable  with  those  for  the  West 
but  it  is  expressly  stated  in  the  bulletin  wherein  the  results  were  pub- 
lished that  in  many  other  counties  of  the  State,  costs  would  be  much 
higher.  The  Agricultural  Experiment  Stations  of  Washington,  Oregon 
and  California  have  none  of  them  issued  bulletins  on  the  cost  of  milk 
production  in  those  States.  A.  B.  Nystrom  of  the  Washington  Station 


186 


CITY  MILK  SUPPLY 


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SANITARY  MILK  PRODUCTION 


187 


says  that  in  Washington  the  cost  of  production  varies  quite  as  much  as  in 
various  parts  of  the  United  States.  The  western  part  of  Washington, 
having  heavy  rainfall,  is  well-adapted  to  dairying  and  so  milk  can  be 
produced  cheaply,  whereas  the  eastern  portion  being  semi-arid  is  not  so 
well-suited  to  the  industry,  consequently  the  production  of  milk  is  more 
costly.  In  parts  of  the  State  a  hundredweight  of  4  per  cent,  milk  can 
be  produced  for  30  cts. ;  in  others  the  cost  would  be  a  dollar. 

Several  of  the  investigations  have  shown  that  the  quantity  of  milk 
produced  per  cow  bears  an  important  relation  to  the  cost  of  production. 
This  is  of  greatest  significance  to  the  dairyman  who  is  not  selling  milk 
on  a  butterfat  basis.  Table  53,  from  the  New  York  study,  illustrates 
the  point  and  the  lesson  it  inculcates  is  that  a  poor-producing  cow  is  an 
expensive  milk  maker  and  therefore  it  behooves  the  dairy  farmer  to 
improve  his  herd. 

TABLE  53. — RELATION  OF  YIELD  TO  COST  OF  PRODUCTION  (HOPPER  AND  ROBERTSON) 


Group 

Number  of 
cows 

Average 
production 

Net  cost  of 
production 

Net  cost, 
per  cent. 

5,000  lb.  or  less  
5,001-7,000  lb  
7,001-9,000  lb. 

159 
360 
214 

4,161 

5,993 

7,843 

$57.20 
74.40 
92  00 

$1.37 
1.24 
1  17 

9,001-1  1,000  lb  
Over  11,000  lb. 

84 
17 

9,763 
12  377 

109.00 
112  60 

1.12 
0  91 

Total 

834 

Average  

6,621 

80.24 

1.21 

The  price  that  the  dairyman  receives  for  his  milk  is  usually  determined 
by  cheese  factories,  creameries  or  large  city  milk  dealers.  Sometimes 
the  price  is  a  matter  of  direct  agreement  between  the  dairyman  and  the 
buyer,  often  it  is  established  after  much  parleying  between  the  pur- 
chaser and  dairymen's  associations.  The  price  is  usually  higher  where 
there  is  competition  for  the  milk  either  between  different  milk  dealers  or 
between  milk  dealers  and  creameries.  Where  a  single  interest  controls 
the  district  the  buyer  virtually  determines  the  price.  The  contract  is 
usually  made  so  that  more  is  paid  for  the  milk  in  some  months  of  the  year 
than  others.  This  is  made  evident  by  Table  54  which  gives  the  average 
prices  paid  for  milk  in  different  sections  of  the  United  States  in  1914. 
According  to  this  table  milk  was  highest  in  December  when  the  price 
was  4.205  cts.  a  quart,  and  lowest  in  June  when  it  fell  to  3.264  cts.  The 
average  price  for  the  year  was  highest  in  New  England,  4.657  cts.  a 
quart,  and  lowest  in  the  Middle  Atlantic  where  it  was  only  2.841  cts. 
One  dealer  in  the  Middle  Atlantic  States  reported  that  in  June  he  paid 
but  90  cts.  a  hundredweight  or  1.9  cts.  a  quart.  The  Middle  Atlantic 


188 


CITY  MILK  SUPPLY 


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SANITARY  MILK  PRODUCTION 


189 


States  show  the  greatest  range  in  prices,  1.363  cts.,  the  December  price 
being  4.204  cts.  and  the  June  price  2.841. 

The  late  G.  M.  Whitaker  investigated  the  extra  cost  of  producing 
clean  milk  and  found  that  to  increase  the  dairy  score  from  42  points  which 
he  believed  should  be  attained  as  a  natural  and  necessary  incident  of 
milk  production,  to  approximately  70  points,  which  he  held  practically 
met  modern  sanitary  requirements,  the  following  added  expenses  would 
be  incurred  in  a  15-cow  dairy. 


4.2 
4.2 

4.1 
4.0 

3.9 

3.7 

3.0 
&6 

3.4 
2.2 
3.2 
2.1 
2.0 
2.9 


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1912- 
1913- 
1914 


Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec. 

FIG.  32. — Average  monthly  prices,  for  the  entire  United  States,  of  milk  in  cents  per 
quart,  at  farmers'  shipping  stations,  in  the  years  1912,  1913,  and  1914. 

(Adapted  from  the  "  Weekly  News  Letter"  of  the  U.  S.  Dept.  of  Agriculture.) 

"  There  may  be  an  added  expense  of  5  cts.  per  cow  per  day  for  labor,  plus,  in 
extreme  cases,  5^  cts.  for  new  or  additional  equipment;  and  if  we  add  5  cts.  more 
to  remunerate  the  proprietor  for  his  extra  care  and  vigilance  there  will  be  an 
extreme  increase  of  15}^  cts.  per  cow  per  day.  The  product  of  a  cow  ranges 
from  4,000  to  10,000  Ib.  of  milk  a  year,  or  from  5  to  12  qt.  a  day.  The  added 
expense  for  labor  would  therefore  amount  to  about  %  to  1  ct.  a  quart,  and  in 
rare  instances  where  great  additional  expense  is  required  for  repairs,  new  con- 
struction, and  new  equipment,  this  might  raise  the  increase  1  to  2  cts.  a  quart 
more.  The  allowance  for  extra  remuneration  to  the  dairyman  for  added  care 
would  bring  the  total  added  expense  per  quart  from  1^  cts.  when  cows  give  large 


190  CITY  MILK  SUPPLY 

amounts  of  milk  to  3  cts.  when  the  cows  are  of  low  production.  The  added 
actual  labor  and  the  remuneration  of  the  proprietor — without  any  new  construc- 
tion or  equipment — would  increase  the  expense  from  1  to  2  cts.  a  quart.  This 
added  expense  of  improved  methods  and  equipment,  however,  would  no  doubt 
be  partly  offset  by  increased  production  and  increased  economy  of  feed,  so  that 
the  net  extra  expense  of  producing  clean  milk  would  probably  be  somewhat  less 
than  the  figures  given." 

Sources 

WARD,  "Invasion  of  the  Udder  by  Bacteria,"  Bull  178,  Cornell  Univ.  Ag.  Expt.  Sta., 

1900. 

BERGEY,  "Source  and  Nature  of  Bacteria  in  Milk,"  Bull  125,  Pa.  Dept.  Ag.,  1904. 
HASTINGS  and  HOFFMAN,  "Bacterial  Content  of  the  Milk  of  Individual  Animals," 

Univ.  Wis.  Ag.  Expt.  Sta.,  Res.  Bull.  6,  June,  1909. 
HARDING  and  WILSON,  "A  Study  of  the  Udder  Flora  of  Cows,"  Tech.  Bull.  27,  N.  Y. 

Ag.  Expt.  Sta.,  March,  1913. 
SHERMAN  and  HASTINGS,   "The  Presence  of  Streptococci  in  the  Milk  of  Normal 

Animals,"  The  Creamery  and  Milk  Plant  Monthly,  vol.  3,  No.  6,  February,  1915. 
ERNEST,  Mohler-Eichhom  "Milk  Hygiene." 
EVANS,  "Bacteria  in  Fresh  Milk  of  Normal  Udders,"  Jour.  Infect.  Diseases,  vol.  18, 

No.  5,  pp.  437-476,  1916. 
HARDING,  WILSON  and  SMITH,  "The  Modern  Milk  Pail,"  Bull.  236,  N.  Y.  Ag.  Expt. 

Sta.,  December,  1910. 
STOCKING,  "Quality  of  Milk  Affected  by  Common  Dairy  Practices,"  Bull.  42,  Storrs 

Ag.  Expt.  Sta.,  June,  1906. 
HARDING,  RHUELE,  WILSON  and  SMITH,  "The Effect  of  Certain  Dairy  Operations  upon 

the  Germ  Content  of  Milk,"  Bull.  365,  N.  Y.  Ag.  Expt.  Sta.,  August,  1913. 
HEINEMANN  and  CLASS,  "The  Bacterial  Content  of  Separator  Cream  and  Separated 

Milk,"  Jour.  Am.  Public  Health  Assn.,  vol.  1,  No.  3,  March,  1911. 
AYRES  and  JOHNSON,  "Removal  of  Garlic  Flavor  from  Milk  and  Cream,"  Farmer's 

Bull.  608,  U.  S.  Dept.  Ag.,  August,  1914. 
BRAINERD,  "The  Production  of  Clean  and  Sanitary  Milk,"  Bull.  185,  Va.  Ag.  Expt. 

Sta.,  September,  1909. 
FRASER,  "Dairy  Conditions  and  Suggestions  for  Their  Improvement,"  Bull.  84,  Univ. 

111.  Ag.  Expt.  Sta.,  February,  1903. 

PARKER,  "Clean  Milk,"  The  Illinois  Agriculturalist,  vol.  16,  No.  5,  February,  1912. 
ERF,  "Milking  Machines,"  Bull.  140,  Kan.  State  College  Ag.  Expt.  Sta.,  1906. 
LANE  and  STOCKING,  "The  Milking  Machine  as  a  Factor  in  Dairying,"  Bull.  92, 

Bureau  Animal  Industry,  U.  S.  Dept.  Ag.,  1907. 

STOCKING  and  BEACH,  "Milking  Machines,"  Bull.  47,  Storrs  Ag.  Expt.  Sta.,  1907. 
HAECKER  and  LITTLE,  "Milking  Machines,"  Bull.  108,  Univ.  Neb.  Ag.  Expt.  Sta., 

1908. 
HASTINGS  and  HOFFMAN,  "The  Milking  Machine  as  a  Factor  in  Milk  Hygiene," 

Cent.  f.  Bakteriologie,  vol.  22,  1908. 
WOLL  and  HUMPHREY,  "Milking  Machine  Experiments,"  Bull.  173,  Univ.  Wis.  Ag. 

Expt.   Sta.,    1909. 

WING,  "Milking  Machines,"  etc.,  Circ.  18,  Cornell  Univ.  Ag.  Expt.  Sta.,  May,  1912. 
HARDING,  WILSON  and  SMITH,  "Milking  Machines,"  etc.,  Bull.  317,  N.  Y.  Ag.  Expt. 

Sta.,  1909. 

SMITH  and  HARDING,  "Milking  Machines,"  etc.,  Bull.  353,  N.  Y.  Ag.  Expt.  Sta.,  1912. 
LARSEN,  WHITE  and  FULLER,  "Preliminary  Report  on  Milking  Machines,"  Bull.  144, 

S.  D.  Ag.  Expt.  Sta.,  1913. 


SANITARY  MILK  PRODUCTION  191 

HOOPER  and  NUTTER,  "Experiments  with  the  Sharpie's  Mechanical  Milker."  Bull. 

186,  Ky.  Ag.  Expt.  Sta.,  1914. 

BREED,  "Cells  in  Milk  Derived  from  the  Udder,"  Bull  380,  N.  Y.  Ag.  Expt,  Sta.,  1914. 
RHUELE  and  KULP,  "Germ  Content  of  Stablt  Air  and  its  Effect  upon  the  Germ  Con- 
tent of  Milk,"  Bull  409,  N.  Y.  Ag.  Expt.  Sta.,  1915. 
PRUCHA  and  WEETER,  "Influence  of  Conditions  in  the  Barn  upon  the  Germ  Content 

of  Milk,"  Jour,  of  Bacteriology,  vol.  1,  No.  1,  p.  109. 
FULLER,  "Underground  Waters  for  Farm  Use,"  W.  S.  Paper  255,  U.  S.  Geol.  Surv., 

1910. 
HANSEN,   "Sanitary  Engineering  and  Agricultural  Engineering."     "Chemical  and 

Biological  Survey  of  the  Waters  of  Illinois,"  vol.  2,  No.  38,  1913,  a  reprint  from 

Univ.  111.  Bull. 
KELLERMAN  and  BECKWITH,  "Bacteriology  of  Dairy  Wells  of  Washington,  D.  C.," 

Eng.  News,  vol.  57,  No.  6,  p.  152,  1907. 
KELLERMAN  and  WHITTAKER,   "Farm  Water  Supplies  of  Minnesota,"   Bull.   154, 

Bureau  Plant  Industry,  U.  S.  Dept.  Ag.,  1909. 
PRESCOTT,  "Farm  Water  Supplies  with  Special  Reference  to  Dairy  Farms,"  Am.  Jour. 

Public  Health,  vol.  3,  No.  9,  September,  1913. 
TULINGER,   "Water  Supply,  Plumbing  and  Sewage  Disposal  for  Country  Homes," 

Bull.  57,  U.  S.  Dept.  Ag.,  1914. 
MELICK,  "Effect  of  Bacteria  in  the  Wash  Water  of  Butter,"  Bull.  138,  Kan.  State  Ag. 

College,  1906. 
LARSEN,  WHITE  and  BAILEY,  "Effect  of  Alkali  Water  on  Dairy  Products,"  Bull.  132, 

S.  D.  Ag.  Expt.  Sta.,  1912. 
DROWN,  "Purification  of  Ice  in  Freezing,"  Jour.  New  England  Water  Works  Assn., 

vol.  8,  No.  1,  1893. 
SEDGWICK  and  WINSLOW,  "Experiments  on  the  Effect  of  Freezing  and  other  Low 

Temperatures  upon  the  Viability  of  the  Bacillus  of  Typhoid  Fever,  with  Con- 
siderations Regarding  Ice  as  a  Vehicle  of  Infectious  Disease,"  Memoirs  of  the 

American  Academy  of  Arts  and  Sciences,  vol.  12,  p.  467,  1902. 
"The  Cost  of  Milk  Production,"  Hoard's  Dairyman,  vol.  48,  No.  23,  Jan.  1,  1915. 
RASMUSSEN,  "Cost  of  Milk  Production,"  Extension  Bull.  2,  N.  H.  State  College,  Expt. 

Sta.,  June,  1913. 
LINDSEY,  "Record  of  the  Station  Herd  and  Cost  of  Milk  Production,"  Bull.  145,  Mass. 

Ag.  Expt.  Sta.,  September,  1913. 
TRUEMAN,  "Records  of  a  Dairy  Herd  for  5  Years,"  Bull.  73,  Storrs  Ag.  Expt.  Sta., 

June,  1912. 
HOPPER  and  ROBERTSON,  "The  Cost  of  Milk  Production,"  Bull.  357,  Cornell  Univ. 

Ag.  Expt.  Sta.,  March,  1915. 
MINKLER,  "Cost  of  Producing  Milk,"  31st  Annual  Report  N.  J.  State  Ag.  Expt. 

Sta.,  64,  67,  1910. 
FRASER,  "Cow  Index  of  Keep  and  Profit,"  Circ.  134,  Univ.  111.  Ag.  Expt.  Sta.,  2d 

Ed.,  1913. 
COOPER,  "The  Cost  of  Minnesota  Dairy  Products,"  Bull.  124,  Univ.  Minn.  Ag.  Expt. 

Sta.,  1911. 
ERF,  "Cost  of  Milk  Production,"  Orange  Judd  Farmer,  vol.  54,  No.  12,  p.  480,  March 

22,    1913.   2d  Annual  Report    International    Association   of    Dairy  and   Milk 

Inspectors,  pp.  11&-126,  1913. 
HARWOOD,  "What  it  Costs  to  Produce  Milk  in  New  England,"  Circ.  9,  Mass.  State 

Board  of  Agriculture,  1914. 
WHITAKER,  "The  Extra  Cost  of  Producing  Clean  Milk,"  Circ.  170,  Bureau  Animal 

Industry,  U.  S.  Dept.  Ag.,  1911. 


192  CITY  MILK  SUPPLY 

BUCKLEY  and  LAMSON,  "Open  Stables  or  Closed  Stables  for  Dairy  Animals:  The  Bac- 
terial Content  of  Milk  Produced  in  the  Open  Stables  and  in  Closed  Stables," 

Bull  177,  Md.  Ag.  Expt.  Sta.,  May,  1913. 
"North's  Milk  System." 
NORTH,  "The  Dairyman  vs.  the  Dairy,"  Am.  Jour.  Public  Health,  vol.  5,  No.  6,  pp. 

519-525,  June,  1915. 
WHITAKER,   "The  Score  Card  System  of  Dairy  Inspection,"  Circ.  199   (Revised), 

Bureau  Animal  Industry,  U.  S.  Dept.  Ag. 
LANE,  "Report  of  Committee  on  Dairy  Farm  Score  Card,"  3d  Annual  Report  of  the 

International  Association  of  Dairy  and  Milk  Inspectors,  1914. 
BRAINERD  and  MALLORY,  "Milk  Standards.     A  Study  of  the  Bacterial  Count  and 

Dairy  Score  Card  in  City  Milk  Inspection,"  V.  P.  I.,  Ag.  Expt.  Sta.,  Bull.  194, 

September,  1911. 
BREW,  "Milk  Quality  as  Determined  by  Present  Day  Score  Cards,"  Bull.  398,  N.  Y. 

Ag.  Expt.  Sta.,  March,  1915. 
GARDNER,  A.  K.,  "Report  of  the  Committee  of  the  Academy  of  Medicine  upon  the 

Comparative  Value  of  Milk  Formed  from  the  Slop  Distilleries  and  other  Food," 

March,  1848. 
Frank  Leslie's  Illustrated  Newspaper,  "Startling  Exposure  of  the  Milk  Trade  of  New 

York  and  Brooklyn,"  May  8,  15,  22,  29;  June  5,  12,  19,  26;  July  3,  10,  17,  24,  31; 

Aug.  7  et  seq.,  1858. 


CHAPTER  V 
THE  TRANSPORTATION  OF  MILK 

The  Hauling  of  Milk. — After  milk  has  been  produced  on  the  farm  it 
must  be  carried  to  the  consumer.  A  considerable  number  of  dairymen 
either  load  the  milk  into  their  own  delivery  wagons  and  retail  it  thenv 
selves  or  dispose  of  it  to  a  neighbor  who  does  so.  Others  take  their 
milk  in  cans  to  a  creamery  or  country  milk  plant  where  it  is  sometimes 
pasteurized  and  almost  always  cooled  after  which  it  is  put  into  other 
cans  or  into  bottles  for  shipment  to  the  city,  but  most  farmers  carry  their 
milk  right  to  the  depot  where  it  is  picked  up  by  milk  trains. 

The  hauling  of  milk  is  a  source  of  expense  to  the  farmer.  A  deal  of 
time  is  wasted  in  those  dairy  districts  where  it  is  the  custom  for  every 
farmer  to  drive  to  the  station  with  the  few  cans  of  milk  that  he  produces. 
In  more  progressive  communities  the  farmers  economize  by  combining 
their  loads,  the  hauling  being  done  either  by  several  neighbors  who  agree 
to  carry  the  milk  in  turn,  or  by  a  driver  who  is  hired  to  haul  it  all.  There 
are  some  objections  to  the  latter  practice  but  they  are  usually  overcome 
where  there  is  a  disposition  to  do  so.  A  careless  driver  may  confuse  the 
lots  of  milk  shipped  by  the  different  farmers  and  a  dishonest  one  may 
tamper  with  the  milk.  Milk  that  is  handled  by  a  truckman  is  often 
exposed  to  deteriorating  influences  of  various  sorts.  He  usually  follows 
the  main  road  and  so  farmers  living  on  branch  roads  bring  their  milk  to 
the  thoroughfare  to  be  picked  up.  Consequently  it  stands  exposed  to 
sun,  rain  and  dust,  to  the  attention  of  animals  and  of  mischievous  persons 
to  its  injury.  The  same  dangers  are  often  encountered  when  milk  is 
left  exposed  and  unguarded  on  railway  platforms. 

Unless  proper  precautions  are  taken  of  milk  in  transit  it  is  apt  to 
be  injured  in  cold  weather  by  freezing,  and  in  warm,  it  is  likely  to  be 
decomposed  by  bacterial  growths. 

The  costs  of  teaming  milk  are  illustrated  in  Tables  55,  56  and  57 
which  are  adapted  from  Bulletin  357  of  the  Cornell  University  Station 
and  also  by  Table  58.  Table  55  gives  the  cost  for  each  of  the  53  farms 
surveyed.  In  Table  56  the  farms  are  grouped  according  to  the  distance 
the  milk  is  carried.  While  there  is  not  a  progressive  increase  in  cost  per 
hundredweight  from  group  to  group,  there  is  so  for  the  %-  to  1-  to  2-  to 
3-  to  4-mile  groups,  which  illustrates  the  tendency  for  the  cost  of  trans- 
portation to  increase  with  the  distance.  Table  58  shows  that  it  costs 
more  for  the  farmer  to  haul  his  own  milk  than  to  hire  it  done, 
is  193 


194  CITY  MILK  SUPPLY 

TABLE  55. — COST  OF  TEAMING  MILK  ON  53  FARMS  IN  JEFFERSON  COUNTY,  NEW 
YORK  (HOPPER  AND  ROBERTSON) 


•    Herd 
number 

Number 
of  cows 

Pounds  of 
milk  teamed 

Miles 
teamed 

Cost  of  man 
labor  for 
teaming 

Cost  of  horse 
labor  for 
teaming 

Cost  of  team- 
ing 100  Ib. 
of  milk 

3 

49 

338,984 

0.25 

$54  .  75 

$87  .  60 

$0  .  042 

32 

28 

230,557 

0.25 

27.45 

21.96 

0.021 

30 

24 

153,867 

0.25 

27.30 

43.80 

0.046 

18 

10 

86,335 

0.25 

21.75 

34.80 

0.066 

36 

10 

77,394 

0.25 

31.50 

25.20 

0.073 

48 

13 

122,293 

0.50 

54.75 

43.80 

0.081 

45 

14 

113,538 

0.50 

45.00 

72.00 

0.103 

47 

17 

168,406 

.00 

23.75 

27.00 

0.030 

20 
35 

13 
11 

166,011 
123,458 

.00 
.00 

54  .  75 
54.75 

87.60 
43.80 

0.086 
0.080 

19 

15 

114,958 

.00 

30.30 

48.48 

0.069 

28 

12 

90,091 

.00 

54.75 

87.60 

0.158 

53 

14 

88,489 

1.00 

54.75 

87.60 

0.161 

16 

7 

86,420 

1.00 

54.75 

43.80 

0.114 

8 

11 

78,146 

1.00 

18.75 

15.00 

0.043 

40 

6 

57,171 

1.00 

54.75 

43.80 

0.131 

37 

8 

51,496 

1.25 

27.30 

43.80 

0.138 

50 

24 

196,995 

1.50 

49.50 

59.40 

0.055 

17 

10 

147,434 

1.50 

21.30 

25.56 

0.032 

49 

20 

125,774 

1.50 

40.95 

32.76 

0.059 

42 

11 

113,178 

1.50 

36.55 

56.88 

0.083 

12 

11 

96,886 

1.50 

27.15 

43.44 

0.073 

11 

12 

72,683 

1.50 

27.30 

21.84 

0.068 

46 

5 

51,974 

1.50 

42.75 

68.40 

0.214 

27 

24 

208,447 

2.00 

56  .  25 

90.00 

0.070 

1 

24 

152,718 

2.00 

81.00 

64.80 

0.105 

14 

19 

138,137 

2.00 

109  .  50 

175.20 

0.206 

34 

14 

77,278 

2.00 

22.80 

36.48 

0.077 

9 

12 

62,478 

2.00 

36.15 

28.92 

0.104 

39 

8 

59,562 

2.00 

57.30 

45.82 

0.173 

5 

23 

186,521 

2.50 

40.95 

65.52 

0.057 

6 

19 

132,532 

2.50 

81.90 

131.04 

0.154 

51 

17 

104,162 

2.50 

42.00 

67.20 

0.105 

43 

12 

69,310 

2.50 

40.50 

43.20 

0.121 

25 

23 

240,637 

3.00 

90.00 

144  .  00 

0.097 

15 

14 

134,970 

3.00 

54.60 

87.36 

0.105 

31 

17 

125,858 

3.00 

135.00 

216.00 

0.279 

10 

15 

124,793 

3.00 

136.50 

218.40 

0.284 

52 

24 

119,174 

3.00 

62.10 

99.36 

0.135 

24 

18 

102,550 

3.00 

164.25 

262  .  80 

0.416 

33 

11 

100,371 

3.00 

51.00 

93.60 

0.144 

22 

14 

82,485 

3.00 

68.25 

109.20 

0.215 

38 

9 

45,577 

3.00 

0.156 

44 

18 

107,981 

3.50 

144.00 

230.40 

0.347 

23 

22 

244,820 

4.00 

135.00 

216.00 

0.143 

29 

12 

168,495 

4.00 

136.87 

219.00 

0.211 

41 

27 

164,070 

4.00 

54.00 

43.20 

0.059 

7 

22 

133,826 

4.00 

117.00 

187.20 

0.227 

4 

15 

114,228 

4.00 

49.50 

79.20 

0.113 

21 

9 

106,875 

4.00 

83.25 

133.20 

0.203 

2 

7 

61,760 

4.00 

49.50 

79.20 

0.208 

26 

17 

119,360 

5.00 

82.35 

131.76 

0.179 

13 

13 

116,579 

5.00 

42.75 

68.40 

0.095 

Total,  53 

834 

6,582,183 

113.50 

S3.160.87 

$4,532.38 

THE  TRANSPORTATION  OF  MILK  195 

TABLE  56. — COST  OF  TEAMING  MILK  ON  53  FARMS  IN  JEFFERSON  COUNTY, 
NEW  YORK  (HOPPER  AND  ROBERTSON) 


Number 
of  herds 

Average  number 
of  pounds  of  milk 
per  farm 

Number  of 
miles  teamed 

Average  cost 
of  man  labor 

Average  cost 
of  horse  labor 

Cost  of  teaming 
per 
hundredweight 
of  milk 

5 

177,827 

0.25 

$32.55 

$42.67 

$0  .  042 

2 

117,916                  0.50 

49.88 

57.90 

0.091 

9                 110,128                  1.00 

44.59 

53.85 

0.089 

1                   51,496 

1.25 

27.30 

43.80 

0.138 

7 

114,989 

1.50 

35.07 

44.04 

0.069 

6 

116,437                  2.00 

60.50 

73.54 

0.115 

4 

123,131                  2.50 

51.34 

76.74 

0.104 

8 

180,109                  3.00 

95.21 

153.84 

0.138 

1 

107,981                  3.50 

144.00 

230.40 

0.347 

7 

142,010                  4.00 

89.30 

136.71 

0.159 

2 

117,970                  5.00 

62.55 

100.08 

0.138 

TABLE  57. — TEAMING  COSTS\PER  FARM,  6,582,183  LB.  OF  MILK  ON  53  FARMS  JEFFER- 
SON COUNTY,  NEW  YORK  (HOPPER  AND  ROBERTSON) 


! 

Number  of  hours 
yearly 

Cost 

Cost  per  hundred- 
weight of  milk 

Man  labor  
Horse  labor 

398 
713 

$59  .  64 
85.52 

$0.048 
0.069 

Total  

1,111 

145.16 

0.117 

Average  length  of  haul,  2.14  miles. 

Rate  per  mile  per  hundredweight,  $0.055. 

TABLE  58. — COST  OF  HAULING  MILK  FROM  148  FARMS  IN  DELAWARE  COUNTY,  NEW 
YORK  TO  CREAMERY  (WARREN) 


Milk  hired  hauled 


Milk  hauled  by  farmer 


Number  of  miles  from 
creamery 

Number  of 
farms 

Cost  for  each  dollar's 
worth  of  milk 

Number  of 
farms 

Cost  for  each  dollar's 
worth  of  milk 

0.5 

19 

$0.047 

1.0 

3 

$0.043 

16 

0.064 

2.0 

12 

0.042 

13 

0.066 

3.0 

18 

0.055 

6 

0.097 

4.0 

12 

0.061 

5 

0.155 

5-6 

24 

0.060 

3 

0.138 

7-8 
9-10 
13.0 

9 
4 
1 

0.065 
0.068 
0.068 

3 

0.199 

A  farmer's  time  counted  at  15  cts.  per  hour. 

A  boy's  time  counted  at  8  cts.  per  hour. 

A  team's  time  counted  at  15  cts.  per  hour  or  8  cts.  per  horse  per  hour.  The  time 
taken  to  get  ready  and  to  hitch  up  as  well  as  the  small  size  of  the  load  makes  the  cost  to 
the  farmer  of  hauling  his  own  milk  very  high. 


196 


CITY  MILK  SUPPLY 


A  charge  of  15  cts.  per  man  and  12  cts.  per  horse  was  made  and  the 
cost  of  teaming  the  milk  for  each  herd  was  calculated  from  all  the  milk 
hauled  from  each  farm  during  the  year  and  the  number  of  men  and  horse 
hours  required  to  move  the  year's  product  of  milk  to  the  factory  or  station. 

Temperature  and  Bacteria  of  Milk  Increase  in  Hauling. — Since 
bacteria  multiply  rapidly  in  milk  at  temperatures  above  50°F.  and 
since  the  rate  of  increase  is  greater  the  higher  the  temperature,  the 
tendency  for  milk  to  warm  up  in  transportation  is  a  serious  matter. 
The  U.  S.  Department  of  Agriculture  in  some  experiments  found  that 
when  milk,  cooled  to  50°F.,  was  hauled  in  an  open  truck  13  miles  on  a 
bright  sunny  day  with  the  temperature  at  82.6°F.,  in  3  hr.,  cans  covered 
with  hair-quilt-jackets  showed  a  rise  in  temperature  of  5.5°,  those  wrapped 
in  wet  burlap  8.5°  and  unprotected  cans  28.5°F.  At  Milwaukee,  Gunn 
studied  this  question  and  some  of  the  measurements  made  by  him  are 
set  forth  in  Table  59. 

TABLE  59. — RISE  IN  TEMPERATURE  OF  MILK  COLLECTED  BY  WHOLESALE  WAGONS  IN 
MILWAUKEE,  Wis.,  AUG.  30,  1911  (GUNN) 


Shippers' 
numbers 

Place  of  collection 

Time  col- 
lected, 
a.m. 

Time 
delivered 

Tempera- 
ture of 
milk  at 
collection, 
°F. 

Tempera- 
ture of 
milk  at 
delivery, 
F. 

I 

Farm  at  roadside 

6:30 

1:05 

56 

64 

4 
5 
6 

7 
8 

Cold  water  tank  at  farm  .  ..... 
From  farmer  at  roadside  
Cold  water  tank  at  farm  
Cold  water  tank  at  farm  
From  farmer  at  roadside  

6:35 
6:50 
6:55 
6:55 
7:00 

11:30 
12:30 
12:50 
12:15 
12:50 

52 
57 
56 
60 
56 

58 
62 
60 
62 
62 

10 
11 

From  farmer  at  roadside  
From  farmer  at  roadside. 

7:15 
7:20 

11:30 
11:20 

45 
53 

56 

58 

12 
14 
15 
17 
18 
19 

From  farmer  at  roadside  
From  farmer  at  roadside  
Cold  water  tank  at  farm.  .  ...I'.',:. 
From  roadside  (unprotected)  .  .  . 
From  farmer  at  roadside  
From  farmer  at  roadside  

7:20 
7:25 
7:30 
7:35 
7:40 
8:10 

11:20 
11:45 
12:00 
12:00 
11:45 
12:15 

48 
61 
56 
58 
59 
60 

60 
63 
62 
60 
56 
62 

20 
21 
22 
25 

Cold  water  tank  at  farm  
Cold  water  tank  at  farm..  .'.;».. 
Cold  water  tank  at  farm  
Cold  water  tank  at  farm.  .  . 

8:20 
8:40 
8:45 
9:40 

12:15 
12:00 
12:30 
12:30 

56 
59 
60 
64 

60 
62 
60 
64 

Air  temperature  at  first  collection,  50°F. 
Air  temperature  at  last  delivery,  70°F. 
To'tal  miles  traveled  to  city  limits,  16. 
Total  time  consumed  on  trip,  5  hr.,  35  min. 

At  Springfield,  Mass.,  Gamble  studied  the  relationship  between  the 
temperature  at  which  milk  is  transported  and  the  bacterial  count.     In 


THE  TRANSPORTATION  OF  MILK 


197 


every  case  the  milk  was  hauled  about  15  miles,  an  uncovered  wagon  being 
used  in  1910,  and  a  covered  one  in  1911  and  1912.  On  Aug.  23,  1910, 
he  took  the  temperatures  of  20  samples  from  twenty  10-qt.  cans  coming 
from  the  different  dairies  and  on  July  27,  1911,  and  July  23,  1912,  under 
similar  atmospheric  and  other  conditions  he  again  took  temperatures  and 
samples  of  the  10-qt.  cans  of  these  same  dairies.  The  counts,  Table 
60  shows,  were  markedly  lower  in  1911  and  1912,  when  the  tempera- 
tures of  the  milk  were  held  between  44°  and  46°F.,  than  they  were  in  1910, 
when  the  temperature  ranged  from  56°  and  64°F. 

TABLE  60. — TEMPERATURE  AND  BACTERIAL  COUNT  OF  THE  MILK  OF  20  DAIRIES  IN 

SPRINGFIELD,  MASS.  (GAMBLE) 


Dairy 
number 

Aug.  23,  1910 

July  27,  1911 

July  23,  1912 

Temperature 

Count 

Temperature 

Count 

Temperature 

Count 

1 

64 

70,000              46 

10,000 

44 

31,000 

2 

64 

20,000             46 

370,000 

44 

40,000 

3 

64 

320,000              46 

400,000 

44 

30,000 

4 

64 

50,000               46 

10,000 

44 

30,000 

5 

64 

460,000             46 

140,000 

44 

20,000 

6 

64 

130,000             46 

27,000 

44 

28,500 

7 

64 

110,000             46 

60,000 

44 

170,000 

8 

64 

10,000             46 

50,000 

44 

45,000 

9 

64 

400,000             46 

250,000 

44 

24,000 

10 

64 

160,000 

46 

10,000 

44 

28,000 

11 

64 

2,000,000 

46 

40,000 

44 

18,000 

12 

64 

8,000,000 

46 

460,000               44 

42,000 

13 

64 

40,000 

46 

30,000 

44 

130,000 

14 

64 

1,200,000 

46 

10,000 

44 

20,000 

15 

56 

80,000 

46 

10,000 

44 

5,000 

16 

56 

330,000 

46 

40,000 

44 

17,000 

17 

56 

70,000     1         46 

40,000 

44 

40,000 

18 

56 

20,000 

46 

140,000 

44 

70,000 

19 

56 

60,000 

46 

50,000 

Discontinued  sending 

20 

56 

10,000 

46 

460,000 

Discontinued  sending 

Average  |         62 

570,000 

46 

130,350 

44                 46,600 

To  show  where  the  increase  in  the  bacterial  count  between  the  farm 
and  the  consumer  takes  place,  Gamble  made  a  bacterial  count  of  samples 
of  milk  drawn  from  10-qt.  cans  in  the  milk  tanks  at  18  different  farms. 
Each  can  was  marked  and  after  it  had  cooled  lJ/£  hr.  in  the  tank  of  the 
city  dealer  it  was  again  sampled.  The  18  cans  were  then  poured  over  and 
from  each  one  of  them  a  quart  bottle  was  filled.  These  18  quart  bottles 
were  then  handled  in  a  routine  way  along  with  the  other  milk  then  being 
bottled  preparatory  to  being  loaded  on  the  delivery  wagons  and  delivered 
to  consumers,  and  they  were  delivered  and  exposed  to  the  air  along  with 


198 


CITY  MILK  SUPPLY 


the  other  milk.  The  next  morning  the  bottles  were  placed  in  an  ice 
box  and  bacteria  samples  were  plated  from  them.  Table  61  gives  the 
results  of  the  experiment.  The  average  temperature  of  the  milk  at  the 
farms  was  higher  than  the  average  temperature  of  the  milk  after  5  hr. 
transportation  and  1J^  hr.  in  the  ice  tanks  of  the  dealer.  The  average 
temperature  of  the  milk  in  the  bottles,  when  placed  in  the  ice  box  at 
7:00  next  morning,  was  14°F.  higher  than  when  it  left  the  tanks  of  the 
dealer.  The  increase  in  bacteria  between  the  dealer  and  consumer  was 
six  times  as  great  as  the  increase  between  the  farm  and  the  dealer's 
tanks. 

TABLE  61. — BACTERIAL  INCREASE  THAT  OCCURS  IN  MILK  BETWEEN  DAIRY  FARM 

AND  MILK  PLANT  AS  COMPARED  WITH  THAT  WHICH  OCCURS  BETWEEN 

MILK  PLANT  AND  CONSUMER  (GAMBLE) 


Dairy 
number 

Temperature 
°F.   at  farm 

Count 

Temperature 
°F.  at  dealer 

Count 

Temperature 
°F.  at  con- 
sumer 

Count 

1 

42 

6,200 

44 

40,000 

58 

130,000 

2 

50 

27,000 

44 

70,000 

58 

120,000 

3 

56 

24,600 

44 

180,000 

58 

800,000 

4 

50 

1,100 

44 

5,200 

58 

10,000 

5 

48 

9,200 

44 

40,000 

58 

80,000 

6 

44 

3,600 

44 

28,000 

58 

50,000 

7 

48 

8,000 

44 

20,000 

58 

110,000 

8 

46 

15,600 

44 

24,000 

58 

70,000 

9 

44 

3,800 

44 

30,000 

58 

60,000 

10 

50 

9,400 

44 

28,600 

58 

210,000 

11 

46 

100,000 

44 

130,000 

58 

240,000 

12 

50 

3,400 

44 

17,000 

58 

120,000 

13 

70 

70,000  (?) 

44 

45,600 

58 

180,000 

14 

40 

5,900 

44 

31,000 

58 

140,000 

15 

42 

9,800 

44 

42,000 

58 

80,000 

16 

44 

18,000 

44 

30,000 

58 

800,000 

17 

44 

10,000 

44 

20,000 

58 

80,000 

18 

48 

43,000 

44 

170,000 

58 

3,200,000 

Average 

46.8 

20,400 

44 

52,800 

58 

360,000 

In  some  of  the  important  cities  of  the  country,  as  for  instance  Rich- 
mond, Va.,  practically  all  of  the  milk  is  hauled  by  wagon  into  the  city; 
in  others  like  Chicago  and  Cleveland  none  of  the  milk  is  handled  in  this 
way.  Between  these  extremes  are  Milwaukee  which  so  receives  40 
per  cent.,  New  Orleans  35  per  cent.,  Detroit  17  per  cent.,  Baltimore  17 
per  cent.,  Boston  9  per  cent.,  Philadelphia  4  per  cent.,  Indianapolis  4 
per  cent,  and  New  York  1  per  cent. 

Use  of  Auto  Truck  in  Hauling  Milk  from  Farm  to  City. — The  auto 
truck  is  being  used  more  and  more  in  bringing  milk  from  outlying  farms 


THE  TRANSPORTATION  OF  MILK 


199 


to  the  city.  Thus  Indianapolis  gets  3  per  cent,  of  its  supply,  Cleveland 
5  per  cent.,  Philadelphia  5  per  cent.,  Baltimore  7  per  cent,  and  Detroit 
8  per  cent,  in  this  manner. 

Transportation  of  Milk  by  Steamboat. — Steamboats  are  little  used 
for  carrying  milk;  Chicago  gets  a  small  quantity  of  milk  that  way  in  the 
summer  months  and  New  York  so  receives  6,000  qt.  daily  which  is  about 
0.2  per  cent,  of  the  entire  daily  supply. 

Transportation  of  Milk  by  Electric  Cars. — Electric  railroads  trans- 
port great  quantities  of  milk.  The  amount  of  milk  that  a  city  receives 
by  electric  roads  depends  on  the  degree  to  which  interurban  traction 
systems  have  been  developed  in  its  vicinity.  In  this  respect  the  cities 


'<&-    •   -2&6Z. 

^          :         ?/fr 


^ 


y^iffS^ 


Courtesy  of  the  Polk  Sanitary  Milk  Co. 

FIG.  33. — Trolley  shipping  station,   at   Mooresville,    Indiana,   in  the   Indianapolis 

dairy  district. 

of  the  middle  west  are  well-served.  Chicago  receives  5  per  cent,  of  its 
supply  over  electric  roads,  Detroit  39  per  cent.,  Cleveland  45  per  cent., 
Indianapolis  68  per  cent.,  whereas  of  the  Eastern  cities  Philadelphia 
receives  only  4  per  cent,  in  this  way  and  Boston,  New  York  and  Baltimore 
none  at  all.  In  some  cases  the  electric  roads  have  made  special  effort 
to  capture  the  milk-carrying  trade  and  have  established  highly  com- 
mendable service.  Often,  however,  nothing  of  the  sort  is  attempted 
and  the  milk  is  handled  very  carelessly.  Trainmen  drink  from  the 
unsealed  cans  and  the  milk  travels  on  platforms  in  the  sun  or  is  stowed 
away  among  a  miscellaneous  parcel  of  baggage  that  is  often  dirty  and 
smelly.  The  stations  where  the  milk  is  picked  up  are  usually  uncovered 
platforms  where  it  is  often  left  exposed  to  the  elements  for  an  hour  or 
more  before  being  loaded  onto  the  cars.  Such  conditions  are  wholly 
unnecessary  and  would  hardly  be  permitted  in  a  district  where  there 


200 


CITY  MILK  SUPPLY 


are  live  milk  inspectors.  Table  62  shows  the  results  of  some  observa- 
tions by  Gunn  on  the  temperature  of  milk  picked  up  at  electric  car 
stations,  en  route  to  Milwaukee.  They  are  briefly,  that  at  an  air  tem- 
perature of  80°F.,  out  of  84  separate  shipments  of  milk,  1.2  per  cent, 
gave  temperature  readings  between  45°  and  49°F.,  23.8  per  cent,  between 
50°  and  59°F.,  55.9  per  cent,  between  60°  and  69°F.,  17.9  per  cent,  be- 
tween 70°  and  79°F.,  or  in  other  words  85.7  per  cent,  of  the  milk  was  at 
a  temperature  favorable  for  bacterial  multiplication. 

TABLE  62. — COLLECTION  OF  MILK  BY  ELECTRIC  RAILWAY  (GUNN) 
Showing  Temperature  of  Milk  at  Time  of  Collection 


Station 

Time,  a.m. 

Temperature  of  milk  in  °F.  when  picked  up  by  train.     Each 
temperature  reading  is  on  the  milk  of  a  single  shipper 

Port  Wash. 

8:25 

67,  63,  64,  66 

24.0 

8:30 

69,  69 

23.0 

8:35 

70,  64 

22.0 

8:50 

82,76 

21.0 

9:00 

68,  78 

18.0 

9:15 

78,  70,  67,  50,  68,  66,  48,  66,  78,  69,  56,  76,  67,  67 

17.0 

9:20 

68,  70,  72 

16.5 

9:30 

60,  58,  64,  66,  56,  64,  50,  52,  64,  66,  64,  70 

16.0 

9:50 

66,  59,  65,  66,  56,  76,  56,  54,  64,  50,  60,  50,  50,  66 

15.0 

9:55 

66,  50,  64,  65,  66,  50,  50,  50,  70,  71,  73,  67 

14.0 

10:00 

66 

Thiensville 

10:05 

67,  67,  56,  55,  64,  66,  65 

Mequon 

10:10 

58,  66,  68,  64 

9.0 

10:20 

68,  70,  56,  66 

8.0 

10:23 

66 

Air  temperature  at  start,  80°.     Distance  traveled,  30  miles. 
Air  temperature  at  finish,  88°.     Time  taken  for  trip,  2  hr. 

Transportation  of  Milk  by  Steam  Railroads. — In  the  smaller  cities 
and  towns  all  the  milk  is  brought  in  by  wagons,  but  as  the  cities  grow  their 
principal  sources  of  milk  supply  are  located  further  and  further  away 
and  more  and  more  of  the  milk  comes  by  steamboat,  electric  railways 
and  steam  railroads.  It  is  estimated  that  about  5  per  cent,  of  the  milk 
supply  of  Indianapolis,  35  per  cent,  of  that  of  Detroit,  50  per  cent,  of 
that  of  Washington,  55  per  cent,  of  that  of  Cleveland,  60  per  cent,  of  that 
of  Milwaukee  and  of  that  of  San  Francisco,  65  per  cent,  of  that  of  New 
Orleans,  75  per  cent,  of  that  of  Baltimore,  of  Cincinnati  and  St.  Louis, 
83  per  cent,  of  that  of  Philadelphia,  90  per  cent,  of  that  of  Boston,  95 
per  cent,  of  that  of  Chicago  and  98  per  cent,  of  that  of  New  York  is 
brought  to  the  city  by  steam  railroad. 

The  first  railroad  in  the  United  States  was  built  in  1825;  from  that 
time  till  the  latter  part  of  1829  the  cars  were  moved  by  horses.  At  that 
date  the  steam  engine  was  introduced  and  thereafter  steam  railroading 


THE  TRANSPORTATION  OF  MILK  201 

developed  rapidly.  It  is  probable  that  the  shipment  of  milk  by  steam 
began  in  a  small  way.  Thus,  H.  N.  Woolman  has  stated  that  in  1855 
his  family  moved  to  34th  and  Bridge  Streets,  now  Spring  Garden,  Phila- 
delphia, and  shipped  milk  to  the  city  on  the  front  platform  of  a  passenger 
car.  This  was  the  first  milk  shipped  over  the  Philadelphia  and  West 
Chester  Railroad.  Whitaker  states  that  Boston  was  probably  the 
first  city  in  the  United  States  to  transport  milk  by  railroad,  the  first 
shipment  being  made  over  the  Boston  and  Worcester  Railroad  in  April, 
1838,  by  Jason  Chamberlain.  He  sold  milk  at  25  cts.  per  can  of  9J^  qt. 
Later  he  sold  his  milk  business  to  Rufus  Whiting.  The  milk  was  shipped 
by  express  in  a  baggage  car.  The  first  milk  car  was  run  soon  after  be- 
tween Westboro  and  Boston  by  a  company  of  peddlers.  Later  the  Boston 
Milk  Co.  ran  a  milk  car  to  Cordaville  and  still  later  Rowell  and  Kelly 
brought  in  milk  from  Northboro  and  Fayville.  In  1843  the  New  England 
Farmer  stated  that  a  single  dealer  brought  to  Boston  over  the  Worcester 
Railroad  200,000  gal.  of  milk  a  year  which  was  estimated  to  be  10  per 
cent,  of  the  city's  entire  supply.  The  milk  brought  20  cts.  a  gallon.  As 
the  population  of  Boston  was  100,000  there  was  a  per  capita  consumption 
of  a  trifle  less  than  %  pt.  a  day.  The  milk  that  came  over  the  Boston 
and  Worcester  Railroad  entered  the  south  side  of  the  city.  On  the  north 
side,  too,  a  milk  business  was  built  up;  milk  was  brought  from  Concord, 
Mass.,  and  from  Wilton,  N.  H.  Business  at  the  latter  place  passed  into 
the  hands  of  David  Whiting  in  1857. 

An  article  reprinted  from  the  Albany  Cultivator  by  the  New  England 
Farmer  of  Sept.  6,  1843,  tells  how  the  growth  of  railroads  had  made  it 
possible  to  ship  milk  a  distance  of  50  miles  to  the  cities  and  have  it  arrive 
in  good  condition.  It  states  that  the  effect  of  this  was  first  felt  in 
Boston  when  milk  was  improved  in  quality  and  reduced  in  price  and  it 
says  further  that  New  York  City  was  beginning  to  receive  the  benefits 
of  milk  shipped  by  rail  from  the  country.  Merritt  states  that  prior  to 
1870  all  of  the  milk  consumed  in  Boston  came  from  a  distance  of  not 
more  than  65  miles.  By  1890  the  Boston  and  Maine  was  bringing  milk 
from  a  distance  of  150  miles  and  in  1910  of  275  miles.  Prior  to  1900 
all  the  milk  for  Boston  carried  by  the  New  York,  New  Haven  and  Hart- 
ford Railroad  came  from  stations  within  34  miles  of  the  city  but  in 
1900  the  furthest  shipping  points  were  85  miles  distant;  in  1910  they 
were  211  miles. 

The  first  train  in  New  York  State  that  was  classed  as  a  rnilk  train 
was  run  over  the  Erie  Railroad  from  Orange  County  to  New  York  City 
in  1847. 

Merritt  says  that: 

"Prior  to  1842  practically  all  milk  consumed  in  New  York  City  was  brought 
in  by  wagons  from  the  surrounding  counties.  In  1842  when  the  Erie  was  under 
construction  one  dealer  shipped  from  Orange  County. 


202 


CITY  MILK  SUPPLY 


"In  a  few  years  the  Harlem  division  of  the  New  York  Central  began  to  haul 
milk  from  the  counties  on  the  west  bank  of  the  Hudson;  at  the  same  time  the 
Newburgh,  Dutchess  and  Connecticut  branch  of  the  Central  New  England  was 
shipping  milk  to  New  York  City  over  the  Hudson  River  branch  of  the  New  York 
Central.  A  few  years  later  the  New  York,  New  Haven  and  Hartford  was  bring- 
ing milk  from  the  New  England  States  to  supply  the  New  York  City  market. 
In  1870  the  Delaware,  Lackawanna  and  Western  received  small  consignments  of 
milk  on  the  Sussex  branch  in  New  Jersey  and  in  the  same  year  the  New  York 
Central  and  Western  started  its  first  milk  train  from  Bloomingburg,  N.  Y. 
Practically  all  of  the  railroads  had  their  farthest  point  from  New  York  within  the 
100-mile  limit  except  that  the  Harlem  was  bringing  milk  from  Rutland,  Vt.,  a 
distance  of  240  miles.  There  was  vejj&r  little  change  in  the  areas  from  which 
milk  was  obtained  until  1890.  In  that  year  the  New  York  Ontario  and  Western 
extended  its  service  to  Walton,  N.  Y.,  a  distance  of  179  miles,  shortly  after  1890 
several  other  railroads  started  milk  trains.  The  Lehigh  Valley  established  this 
service  with  Dryden,  N.  Y.,  as  a  terminus.  In  1893  the  Delaware  and  Hudson 
was  receiving  milk  and  forwarding  it  to  New  York  City  over  the  Delaware. 
Lackawanna  and  Western.  In  1890  the  West  Shore  extended  its  service  beyond 
Albany  with  Syracuse  as  a  starting  point,  and  2  years  later  the  Hudson  River 
branch  of  the  New  York  Central  extended  its  service  to  the  same  point.  By 
1910  many  of  the  points  from  which  milk  was  shipped  to  New  York  City  were 
over  300  miles  distant.  Table  63  shows  the  growth  of  the  business  on  the  prin- 
cipal railroad  lines." 

TABLE  63. — NUMBER  OF  MILLION  GALLONS  OF  MILK  AND  CREAM  RECEIVED  AT  NEW 

YORK  CITY  (MERRITT) 
(Cream  not  reduced  to  terms  of  milk) 


Railroad 

1885-89 

1890-94 

1895-99 

1900-04 

1904-09 

Total 

New  York  Central  

14.0 

12.3 

10.1 

23.2 

36.1 

Delaware,  Lackawanna  &  Western  .  . 

2.1 

12.0 

20.0 

17.9 

25.3 

Erie 

15.0 

17.0 

15.9 

18.2 

23.6 

New  York  Ontario  &  Western 

6  0 

9.9 

14.6 

18.2 

22.2 

Lehigh  Valley                  

0.5 

3.0 

7.1 

13.3 

West  Shore                                 

3.0 

5.1 

6.4 

6.8 

8.5 

New  York,  Susquehanna  &  Western 

5.1 

5.9 

7.0 

7.6 

7.7 

New  York,  New  Haven  &  Hartford 

3.9 

2.4 

4.2 

4.3 

6.0 

Ramsdell  Boat  Line  

1.5 

2.7 

2.6 

2.5 

1.7 

Central  R.  R.  of  New  Jersev  

1.8 

1.0 

1.0 

0.7 

0.4 

Long  Island  R.  R  

1.5 

1.1 

0.3 

Other  sources  

3.3 

2.4 

2.2 

2.2 

2.3 

Total                                           .  «.  J.- 

57.3 

72.3 

87.2 

108.8 

147.2 

PhUadelphia.— "  Prior  to  1870  Philadelphia  was  receiving  its  milk  from  an 
area  within  a  radius  of  50  miles  of  the  city  and  the  greater  part  of  the  milk  re- 
ceived was  transported  by  the  railroad.  Prior  to  1910  the  farthest  points  on  the 
Pennsylvania  System  from  which  milk  was  shipped  to  Philadelphia  were  near 


THE  TRANSPORTATION  OF  MILK 


203 


Harrisburg  and  Reading  in  Pennsylvania,  and  Milford,  Princeton,  Hightstown, 
Bridgeton  and  Salem  in  New  Jersey.  But  in  1911  the  area  was  extended  until 
it  reached  points  in  New  York  State  within  a  few  miles, of  Buffalo.  In  1910  the 
Reading  System  was  drawing  its  milk  for  Philadelphia  over  practically  as  large 
an  area  as  was  the  Pennsylvania. 

"Table  64  shows  the  growth  of  the  business  of  shipping  milk  by  railroad  to 
Philadelphia." 

TABLE  64. — GROWTH  OF  RAILROAD  MILK  BUSINESS  IN  PHILADELPHIA  (MERRITT) 
(Number  of  million  gallons  of  milk  received  in  Philadelphia) 


Railroad 

1890-94 

1895-99 

1900-04 

1905-09 

Pennsylvania  System 

9  4 

9  6 

11  2 

14  2 

Philadelphia  and  Reading  R.  R  
Baltimore  &  Ohio  R.  R  ,  .  ..  v.  .-. 
Wagons  .  ,  . 

9.1 
1.4 
2.6 

8.8 
1.6 
2.1 

9.6 
1.6 
1.7 

12.6 
2.6 
1.5 

Trolley  lines  at  63d  and  Market  Streets 

1  2 

Lehigh  Valley  R.  R.  via   Philadelphia  &   Reading 
R.  R  ."..,:......,...  
Adams  Express  Co 

0.5 

2.0 

2.5 

0.8 
0  5 

U.  S.  Express  Co  

0.1 

Total  

23.1 

24.0 

26.7 

33.6 

In  the  United  States,  the  shipment  of  milk  by  steam  railways  increased 
steadily  and  milk  trains  became  part  of  the  regular  business  equipment 
of  all  railroads  tapping  the  dairy  districts.  Though  the  percentage  of 
milk  that  was  brought  in  by  rail  increased  steadily,  consumers  were  long 
prejudiced  against  railroad  milk  for  much  of  it  was  produced  in  an 
insanitary  way,  was  carelessly  handled  in  transit  and  was  not  properly 
cared  for  by  the  contractors  who  sold  it.  in  many  cities  dairies  persisted 
within  the  city  limits  and  in  the  suburbs.  In  some  cases  a  considerable 
percentage  of  the  milk  came  from  slop  dairies.  Thus  in  Boston  they  were 
forbidden  in  1859,  but  in  New  York  they  were  not  prohibited  till  1873, 
As  late  as  the  90's  probably  most  of  the  milk  came  from  distances  of  not 
greater  than  100  miles  but  with  the  growth  of  the  cities  and  the  advent 
of  improved  methods  in  producing  the  milk  and  shipping  it  and  the  de- 
velopment of  proper  facilities  for  handling  it,  milk  has  come  from  greater 
and  greater  distances  and  in  better  condition  till  now  daily  shipments 
are  made  from  dairy  districts  200  to  400  miles  away. 

Some  Economic  Features  of  Transportation  of  Milk  by  Railroad.— 
Harbison  has  outlined  some  features  of  the  transportation  of  milk  by 
rail.  "It  moves  every  day  in  the  year  and  in  such  regular  quantities  that 
the  maximum  of  use  and  economy  is  obtained  from  a  limited  amount 
of  railroad  equipment.  This  is  in  marked  contrast  to  the  movement  of 
grain  and  many  other  commodities  which  is  very  heavy  at  some  seasons 


204 


CITY  MILK  SUPPLY 


and  very  light  at  others.  The  facilities  for  milk  require  comparatively 
little  capital.  The  country  loading  platforms  are  very  simple  and  inex- 
pensive; the  terminals  are  mostly  wooden  sheds  without  sides,  and  with 
a  minimum  of  platform  space.  As  the  milk  must  be  removed  immediately 
after  arrival  in  the  city,  expensive  storage  warehouses  in  congested  dis- 
tricts are  not  required.  The  cars  that  are  used  in  carrying  milk  are 
mostly  old  ones  that  have  been  diverted  from  other  purposes.  The 
traffic  is  so  regular  that  only  a  minimum  of  rolling  stock  is  necessary  to 
care  for  fluctuations  in  business.  The  cars  are  promptly  released  at  the 
terminals  and  on  arrival  in  the  country  are  loaded  forthwith." 

"Most  cars  make  a  round  trip  daily.     The  labor  cost  of  handling  the 
business  is  low  for  in  the  country  the  shippers  load  their  own  milk  and 


From  the  40th  Annual  Report  of  the  Health  Department   of  the  City  of  Boston. 

FIG.  34. — A  railroad  receiving  station  in  Vermont  that  protects  the  milk  from  sun 

and  storm. 

in  the  city  the  dealers  help  unload.  The  contractors  accept  delivery  at 
terminals  selected  by  the  carrier;  very  little  milk  is  delivered  at  passenger 
terminals.  So  much  milk  comes  out  of  a  dairy  district  that  it  can  usually 
be  carried  in  trainload  lots  which  makes  the  traffic  desirable.  Milk 
is  a  necessity  therefore  it  should  have  the  benefit  of  the  accepted  traffic 
principle  that  agricultural  necessities  should  be  carried  at  the  lowest 
tariffs  consistent  with  a  reasonably  profitable  return  on  the  capital 
employed  in  moving  them.  Despite  this  there  is  some  evidence  of  a 
tendency  for  the  railroads  to  increase  the  rates." 

In  general  the  milk  that  is  shipped  by  rail  is  handled  in  cans  which 
under  the  best  practice  are  washed  and  sterilized  in  the  cities  and  re- 
turned to  the  farmer  who  fills  them  with  milk  and  carries  them  to  the 


THE  TRANSPORTATION  OF  MILK 


205 


train.  Sometimes  milk  is  delivered  at  the  cars  by  a  general  collector 
for  a  district  and  in  some  places  the  cases  are  filled  at  the  siding  of  a 
creamery  which  has  received  the  milk  from  the  farmer,  cooled,  standard- 
ized, pasteurized  and  recanned  it.  A  considerable  percentage  of  the 
milk  of  some  cities,  notably  Chicago,  is  shipped  from  country  milk  plants 
ready  for  delivery.  In  most  cases  it  is  the  intention  of  the  farmer  to 
deliver  the  milk  at  the  station  platform  shortly  before  the  train  is 
scheduled  to  leave  but  the  milk  is  often  left  exposed  for  a  long  time  both 
at  points  where  it  is  picked  up  and  at  which  it  is  delivered.  Kelly  tells 
of  an  instance  that  came  under  his  observation  where  a  shipment  of  milk 
that  was  not  refrigerated  in  transportation  arrived  at  the  city  terminal 
with  a  temperature  of  65°F.  and  was  unloaded  onto  an  uncovered  plat- 
form where  half  of  it  remained  over  an  hour  and  a  half  acquiring  a  tem- 
perature of  85  to  90°F.  Such  occurrences  are  far  from  exceptional. 

Temperature  of  Milk  in  Transit  by  Rail. — This  question  of  keeping 
the  milk  in  transit  from  the  country  to  the  city  at  low  temperature  is 
important.  The  board  of  health  of  Baltimore,  Md.,  in  1911  made  a 
special  investigation  of  conditions  under  which  milk  was  shipped  by  rail 
to  that  city.  Temperatures  of  79  shipments  of  milk  were  taken  as  soon 
as  they  were  loaded  on  the  cars,  and  again  when  the  train  reached  the 
city.  No  means  of  cooling  the  cars  or  the  milk  was  provided  and  the 
temperature  of  the  cars  ranged  from  69°  to  71°F.  The  time  occupied 
in  bringing  milk  from  the  most  distant  shipping  station  was  2  hr.  and  15 
min.  A  summary  of  the  observation  appears  in  Table  65. 

TABLE  65. — TEMPERATURE  OF  MILK   WHEN  LOADED  ABOARD  RAILROAD  CARS  AT 
COUNTRY  SHIPPING  STATION  AND  ON  ARRIVAL  AT  TERMINALS  IN  BALTIMORE,  MD. 

(THOMAS) 


Temperature  of  car 

Railroad  A. 
J71°F. 

Railroad  B. 
70°-71°F. 

Railroad  C. 
69°-71°F. 

Time  of  first  temperature  
Time  of  final  temperature 

6:40  a.m. 
8:40-9  00 

6:30  a.m. 
8  '45-9  '00 

6:45  a.m. 
8*10-8  '25 

Average  initial  temperature  
Average  final  temperature 

64.7° 
66*5° 

59.6° 

62  8° 

62.2° 
64  1° 

Average  rise  in  temperature  
Maximum  initial  temperature 

1.8° 
86  5° 

3.9° 
75  2° 

2.4° 

77  0° 

Maximum  final  temperature  

82.5° 

73.0° 

76  0° 

Minimum  initial  temperature  
Minimum  final  temperature 

46.0° 
54  5° 

44.7° 
52  0° 

58.0° 
61  0° 

Maximum  rise  in  temperature  
Minimum  rise  in  temperature  

8.5° 
-4.0° 

7.3° 

-2.2° 

4.0° 
-5.0°. 

The  shipments  showing  the  maximum  initial  temperatures  had  also 
the  maximum  final  temperatures,  as  would  be  expected,  and  showed  the 
minimum  rise  in  temperature,  this  being  in  each  case  a  negative  quantity, 


206 


CITY  MILK  SUPPLY 


that  is,  the  milk  became  cooler,  since  the  original  temperature  was  higher 
than  that  of  the  car  and  of  the  surrounding  cans.  Likewise  the  ship- 
ments showing  the  minimum  initial  temperatures  had  also  the  minimum 
final  temperatures,  but  showed  the  maximum  rise  in  temperature.  The 
cans  were  closely  packed  in  the  car,  and  the  temperature  of  the  car  had, 
in  most  cases,  but  little  effect  upon  the  temperature  of  the  milk. 

Sharwell  followed  four  cans  of  milk  from  Baldwinsville,  N.  Y.,  to 
Newark,  N.  J.,  a  distance  of  340  miles.  The  milk  was  produced  in  four 
barns  three  of  which  had  scores  of  between  65  and  70;  they  were  fairly 
clean  but  the  cows'  udders  were  not  wiped  off  nor  were  small-top  milk 
pails  used.  The  fourth  barn  scored  but  55  and  was  very  dirty  as  was 
the  method  of  handling  the  milk.  None  of  the  dairies  had  milk  houses 
nor  was  the  milk  cooled.  The  milk  was  set  alongside  the  road  to  be 
picked  up  by  a  truckman  who  carried  it  to  the  creamery.  On  its  arrival 
there  the  milk  was  thrown  into  a  receiving  vat,  run  over  a  cooler  and 
was  caught  in  its  original  can  which  on  being  filled  was  put  in  a  concrete 
tank,  containing  water  and  floating  ice,  to  cool.  In  handling  the  milk 
at  the  creamery  no  pains  were  taken  to  protect  it  from  contamination. 
The  car  on  which  the  milk  was  shipped  is  iced  once  in  a  round  trip  of 
680  miles.  At  the  beginning  of  the  journey  the  car,  though  there  were 
only  50  Ib.  of  ice  in  the  bunkers,  had  a  temperature  of  50°F.  because  of 
the  coolness  of  the  milk  and  the  chunks  of  ice  put  on  top  of  the  cans.  The 

TABLE  66. — INCREASE  IN  BACTERIAL  CONTENT  or  MILK  IN  TRANSIT  BY  RAILROAD 
FROM  BALDWINSVILLE,  N.  Y.,  TO  NEWARK,  N.  J.  (SHARWELL) 


Bacteria  per  cubic 
centimeter  in  the 
milk  of  the  four  cans 

Remarks 

Temperature  in  °F  of  the  four  cans 
of  milk  on  arrival  at  the  creamery, 
88°,  86°,  86°,  84° 
When  put  aboard  the  car,  50°  A.     5,400,000 
B.     5,400,000 
C.     4,500,000 
D.     1,530,000 
At  Binghamton  A.     9,000,000 

Average  count  of  the  four  cans 
as  the  milk  left  the  creamery, 
4,207,500  bacteria  per  cubic 
centimeter. 
Average  bacterial  count  of  the 

B.     7,700,000 
C.    13,700,000 
D.    16,000,000 
At  Newark,  55°,  56°,  56°,  58°  A.    19,300,000 
B.    15,700,000 
C.    18,000,000 
D.  25,000,000 
Half  emptied  cans  in  shops  (  A.    19,900,000 
B.   34,000,000 
C.   75,000,000 

four  cans  after  7  hr.   travel, 
11,600,000  bacteria  per  cubic 
centimeter. 
Average  bacterial  count  of  the 
four  cans,  19,500,000  bacteria 
per  cubic  centimeter. 

Average  bacterial  count  of  the 
four    cans,     49,475,000    bac- 
teria per  cubic  centimeter. 

D.  68,000,000 


THE  TRANSPORTATION  OF  MILK 


207 


temperature  gradually  rose  to  65°F.  The  car  was  iced  at  noon  at 
Chenango  Forks  and  as  Mr.  Sharwell  left  the  train  at  Binghamton  the 
effect  of  the  icing  can  only  be  judged  by  the  fact  that  when  the  milk 
arrived  in  Newark  three  of  the  cans  had  a  temperature  of  56°F.  and  one 
of  58°F.  From  the  terminal  the  four  cans  were  taken  to  four  shops  where 
the  milk  was  sold  as  " loose"  milk;  the  bacterial  content  of  the  milk  was 
tested  when  the  cans  were  half  empty.  The  increase  in  bacteria  in  each 
of  the  four  cans  of  milk  in  the  course  of  the  journey  from  the  farm  to  the 
shops  is  shown  in  Table  66. 

Types  of  Cars  Used  in  Transporting  Milk. — The  cars  in  which  milk 
is  carried  are  of  different  construction.  Small  shipments  often  go  in 
baggage  or  express  cars. 


Courtesy  of  J.  O.  Jordan. 

FIG.  35. — Office  of  old  style  New  England  milk  car. 

None  of  the  refrigerator  cars  used  are  designed  to  cool  the  milk  in 
transit;  they  merely  hold  the  milk  at  about  the  temperature  it  has  when 
put  aboard.  There  are  two  types  of  refrigerator  cars  in  common  use. 
One  is  the  ordinary  baggage  type  of  car  that  has  little  or  no  insulation 
and  so  is  used  for  short  hauls.  The  cans  are  set  on  the  floors  and  in  hot 
weather  have  crushed  ice  packed  around  them.  As  the  ice  melts  the 
water  runs  out  at  the  doors  or  through  cracks  in  the  floors.  The  other 


208 


CITY  MILK  SUPPLY 


has  ice  bunkers  or  brine  tanks  in  the  ends  of  the  cars  and  a  ratio  of  ice 
to  loading  capacity  of  about  1  to  11  cu.  ft.  In  some  of  the  more  recent 
cars  a  mixture  of  salt  and  ice  is  used  to  obtain  lower  temperature  than 
can  be  had  with  ice  alone. 

Whitaker  described  the  milk  cars  in  use  in  New  England  in  1905 
as  being  48  ft.  long,  inside  measurement,  and  in  the  center  having  an 
office  8*/2  by  9  ft.  This  was  provided  with  two  windows  on  each  side. 
In  each  car  were  eight  closets,  each  3^  by  4  ft.  and  with  two  shelves 
accommodating  three  tiers  of  8^-qt.  cans,  the  capacity  of  each  closet  being 


Courtesy  of  J.  O.  Jordan. 

FIG.  36. — Old  style  car  used  for  transporting  milk  in  New  England,  showing  cans  on 
floor  and  in  closet,  and  clerk  in  office. 

90  cans,  making  the  total  capacity  of  the  car  720  cans.  There  were  two 
doors,  3)^  ft.  wide,  opening  to  a  space  in  each  end  of  the  car  for  receiv- 
ing the  cans,  storing  and  breaking  ice  and  for  handling  the  cans.  As 
the  floor  space  in  the  closets  was  utilized  the  usual  carload  was  960  cans. 
This  type  of  car  has  all  but  disappeared;  the  cars  have  been  rebuilt  so 
that  they  have  an  office  in  the  middle  on  both  sides  of  which  the  milk  is 
stored.  They  have  a  capacity  of  1,050  8j^-qt.  cans.  The  type  of  car 
that  is  in  ordinary  use  in  New  England  is  a  large  refrigerator  car 
with  doors  at  each  end  and  an  office  at  one  end.  It  carries  stacked  1,500 
8^-qt.  cans  uniced  or  1,300  iced.  The  new  type  car  is  a  refrigerator  car 
with  the  door  in  the  middle  and  no  office;  it  carries  308  40-qt.  cans. 


THE  TRANSPORTATION  OF  MILK 


209 


None  of  these  three  types  of  cars  has  ice  bunkers;  the  milk  is  kept  cool 
in  summer  by  putting  ice  right  on  top  of  the  cans.  A  car  that  is  coming 
into  use  and  is  giving  good  satisfaction,  both  because  of  the  excellent 
condition  in  which  it  keeps  the  milk  and  because  of  its  economy,  is  the 
tank  car.  A  glass-lined  steel  tank  covered  with  asphalted  cork  brick 
that  are  wired  on  to  the  tank,  is  mounted  in  an  ordinary  refrigerator  car. 
The  tank  is  cylindrical  with  rounded  ends  and  holds  12,486  qt.  of  milk 
or  1,469  cans.  Milk  shipped  in  these  tank  cars  at  38°  to  45°F.  arrives 
in  Boston  at  the  end  of  a  175-mile  trip  with  a  temperature  that  is  not 


Courtesy  of  J.  O.  Jordan. 
FIG.  37. — Ordinary  type  of  car  used  for  transporting  milk  in  New  England. 

over  2°F.  higher  than  the  initial  temperature;  furthermore,  at  the  low 
temperature  that  is  maintained  in  transit  there  is  no  churning  of  the 
milk.  The  greatest  difficulty  in  the  use  of  these  cars  is  to  secure  enough 
milk  at  the  point  of  loading  to  fill  the  tank;  to  pick  up  milk  at  different 
points  en  route  would  result  in  materially  raising  the  temperature  and 
in  the  milk  arriving  at  its  destination  in  poor  condition. 

Mr.  Zippel,  General  Agent  of  the  Milk  Department  of  the  Delaware, 
Lackawanna  and  Western  Railroad,  in  1910  described  the  methods,  which 
are  practically  unchanged  at  the  present  time,  of  transporting  milk  by 
rail.  The  standard  car  is  42  ft.  over  the  end  sills,  with  steel  underframe, 
and,  saving  for  high-speed  air  brakes,  is  from  the  floor  down  exactly  like 
a  first-class  passenger  coach.  These  cars  have  a  capacity  of  300  40-qt. 

14 


210 


CITY  MILK  SUPPLY 


cans  or  550  12-qt.  boxes  of  bottled  milk.  The  cars  have  end  and  side 
doors,  beveled  and  cushioned  with  canvas,  opening  inward  to  facilitate 
handling  at  the  platforms,  and  a  large  ice  bunker  in  each  corner.  These 
bunkers  are  filled  at  the  icing  stations  by  removing  the  hatches  which 
on  the  inside  are  beveled  and  cushioned  with  canvas. 

A  specially  designed  ventilating  system  insures  uniform  melting  of 
the  ice  and  thereby  gives  proper  refrigeration.  Insulation  is  provided 
by  building  the  car  with  an  outside  sheathing  of  yellow  poplar  %  in. 
thick  next  which  is  an  air  space  of  2J-^  in.  that  is  separated  from  a  second 
air  space  of  1%  m-  by  a  sub-lining  of  white  pine  covered  with  Hydrex 
felt  and  sheathed  inside  with  white  pine. 


Courtesy  of  J.  O.  Jordan. 
FIG.  38. — New  type  of  car  used  for  transporting  milk  in  New  England. 

Some  railroads  place  the  ice  directly  on  the  cans  instead  of  using 
bunkers.  Experiments  were  made  at  one  time  by  one  of  the  railroads 
to  determine  whether  the  color  of  the  car  influenced  the  temperature 
but  it  was  found  not  to  do  so. 

The  milk  cars  of  the  Lackawanna  are  run  on  passenger  trains,  or  as 
solid  milk  trains  on  passenger  time.  The  trains  are  in  charge  of  a  milk 
messenger  or  train  agent  whose  duties  are  similar  to  those  of  an  express 
messenger  and  the  service  is  of  the  character  rendered  by  express  com- 
panies except  that  the  milk  is  called  for  by  the  consignees  instead  of 
being  delivered  by  the  company. 

In  making  up  milk  trains,  wherever  carload  shipments  are  made,  a 


THE  TRANSPORTATION  OF  MILK  211 

car  is  supplied,  which  is  cleaned,  loaded  and  iced  by  the  consignor,  the 
rate  on  such  shipments  being  12J^  per  cent,  less  than  that  charged  by 
L.C.L.  shipments.  The  rest  of  the  cars  are  distributed  at  convenient 
points  along  the  line,  the  creameries  at  which  they  are  left  cleaning  the 
car  and  loading  the  output,  to  which  other  consignments  are  added  until 
the  car  is  filled.  Then  the  car  is  locked  and  carried  to  its  destination 
where  the  milk  is  unloaded,  the  cars  cleaned  and  the  empty  cans  and 
boxes  loaded  for  return  to  the  shipping  stations. 

Milk  is  on  the  road  8  to  15  hr.  according  to  the  distance  traveled. 
At  the  terminal  in  Hoboken  there  is  a  large  force  of  cashiers,  foremen  and 
milk  handlers  to  care  for  the  business;  the  handling  is  all  done  at  night, 
the  cars  arriving  between  9:30  and  10:30  p.m.  and  returning  between 
3:30  and  3:50  a.m. 

The  Pennsylvania  Railroad  in  1914,  daily  hauled  over  265,000  qt.  of 
milk  into  Baltimore,  Philadelphia,  Jersey  City  and  the  Borough  of 
Brooklyn.  Prior  to  November,  1911,  when  the  road  established  the 
office  of  milk  agent,  the  company  hauled  no  milk  into  Philadelphia  from 
points  north  or  west  of  Harrisburg,  Pa.,  and  no  shipments  of  milk  from 
any  points  on  the  railroad  were  made  into  New  York  and  Brooklyn. 
Between  these  dates,  an  interval  of  2J^  years,  with  the  cooperation  of 
milk  dealers  of  New  York,  Brooklyn  and  Philadelphia  53  shipping  sta- 
tions representing  an  investment  of  $450,000  were  located  in  the  dairy 
sections  of  northwestern  Pennsylvania,  New  York  and  the  Maryland- 
Delaware  peninsula.  To  develop  this  long-haul  traffic  the  railroad  in 
1912-13  built  at  the  cost  of  $7,665  per  car,  36  all-steel  refrigerator  cars 
which  in  the  autumn  of  the  latter  year  were  put  in  service.  These  cars 
have  two  refrigerating  compartments,  each  with  a  floor  capacity  of  160 
46-qt.  cans,  13  in.  in  diameter.  The  volume  of  the  refrigerating  compart- 
ment is  1,468  cu.  ft.  The  brine  tanks  are- two  in  number  and  have  a 
radiating  surface  of  226  sq.  ft.  and  a  volume  of  77.25  cu.  ft.  The  screened 
portion  above  the  tanks  has  a  volume  of  9.42  cu.  ft.  making  a  total  capacity 
of  86.67  cu.  ft.,  or  a  total  volume  capable  of  holding  3,814  Ib.  of  crushed 
ice,  weighing  44  Ib.  per  cu.  ft.  The  ratio  of  tank  radiating  surface  to 
loading  volume  is  1  sq.  ft.  to  7.48  cu.  ft.,  and  the  ratio  of  ice  to  milk  is 
2  Ib.  of  ice  to  8.6  Ib.  or  1  gallon  of  milk.  The  tanks  have  a  2-in.  free  air 
space  around  them  and  are  15  in.  above  the  floor.  They  are  separated 
from  the  storage  rooms  by  a  partition  open  at  the  top  and  bottom  and 
screened,  thus  creating  a  circulation.  All  moisture  from  tanks  is  carried 
off  from  drip  pan  through  drain  pipes  and  traps.  The  tanks  are  connected 
by  a  IJ^-in.  pipe,  creating  some  circulation  between  them.  This  pipe 
also  regulates  the  brine  to  a  uniform  height  in  both  tanks,  the  height  of 
pipe  above  the  bottom  of  the  tank  being  arranged  so  that  a  certain  amount 
of  brine  remains.  A  riser  connection  to  the  pipe  forms  an  overflow. 

When  refilling  the  tanks,  the  valve  in  the  pipe  connecting  the  tanks 
is  opened  and  all  water  or  brine  above  the  horizontal  pipe  is  drained  off. 


212  CITY  MILK  SUPPLY 

Before  refilling  the  tanks  with  crushed  ice  and  salt  the  valve  is  closed 
again,  causing  the  warm  water  to  rise  to  a  height  equal  to  the  top  of  the 
pipe.  Any  surplus  water  runs  off  through  the  overflow  pipe  and  out- 
side the  pipe  without  egress  of  air.  The  valve  is  manipulated  by  a  rod 
and  universal  joints  from  the  roof  of  the  car  by  removing  the  plug  door. 

When  the  tanks  are  cleaned,  the  round  plugs  at  the  bottom  are 
unscrewed  about  J4  in.,  when  they  release  the  brine;  after  it  has  drained 
off,  the  plug  can  be  entirely  unscrewed  and  the  settlings  removed. 

In  order  that  the  car  can  be  kept  in  a  sanitary  condition  the  floor  is 
covered  with  galvanized  sheet  iron,  all  crevices  being  soldered,  and  after 
each  trip  or  shipment  of  milk  the  floors  are  scrubbed. 

With  this  type  of  car  a  temperature  of  35°  or  40°F.  can  be  maintained. 

The  milk  cars  that  the  writer  has  inspected  in  Chicago  have  been 
very  like  ordinary  baggage  cars;  in  some  of  them  a  hinged  shelf  was  at- 
tached to  the  side  of  the  car  to  hold  cans. 

Rates  of  Transporting  Milk. — The  transportation  of  milk  in  New 
England  was  recently  investigated  by  the  Boston  Chamber  of  Commerce. 
The  great  milk-producing  territory  was  found  to  be  Maine,  New  Hamp- 
shire, Vermont,  Quebec  and  eastern  New  York,  and  the  great  consuming 
territory  to  be  the  163  incorporated  cities  and  towns  of  Massachusetts, 
Rhode  Island  and  Connecticut,  which  together  have  a  population  between 
5  and  6  millions.  About  75  cars  of  milk  move  daily  in  New  England  and 
of  these  about  60  come  to  Boston.  Milk  is  carried:  (1)  as  express;  (2) 
as  excess  baggage;  (3)  in  leased  cars;  (4)  under  the  Massachusetts  Saun- 
ders  law  by  which  a  per  can  rate  is  charged  and  the  railroad  unloads  and 
ices  the  cars. 

The  shipping  rates  that  prevail  are  very  different ;  some  railroads  have 
a  single  rate,  a  passenger  or  a  freight  rate;  others  deduct  25  per  cent,  for 
all  shipments  by  freight.  Some  rates  are  on  a  zone,  while  others  are  on  a 
flat,  per  mile  basis.  Some  railroads  charge  the  same  rate  for  milk  and 
cream  and  others  charge  a  higher  rate  for  cream. 

The  Chamber  finds  it  probable  that  cream  and  some  milk  will  be 
shipped  by  express  and  advises  that  containers  which  may  be  insulated 
or  covered  to  keep  down  the  temperature  be  used.  The  shipping  as 
excess  baggage  is  usually  unsatisfactory  because  of  the  high  temperature 
in  summer  and  the  difficulty  of  grading  but  some  cream  and  some  local 
milk  is  shipped  in  this  manner. 

The  leased  car  system  by  which  the  greater  part  of  the  milk  and  cream 
in  New  England  is  transported  has  tended  to  give  the  city  milk  dealers  a 
monopoly  of  the  business  in  the  buying  territory  and  in  75  per  cent,  of 
it  this  monopoly  is  already  established;  the  farmer,  finding  it  impos- 
sible to  secure  competitive  bids,  has  had  to  accept  the  city  milk  dealers 
terms.  The  many  short  branch  railroads  along  which  but  one  car  of 
milk  is  produced  have  helped  create  this  system  which  tends  to  engender 


THE  TRANSPORTATION  OF  MILK  213 

strife  betwixt  the  farmer  and  dealer  and  to  make  the  farmer  less  ambitious 
to  produce  superior  milk. 

The  Saunders  law  which  was  enacted  in  Massachusetts  in  1910  com- 
pels the  railroad  to  load,  unload  and  ice  milk  and  to  furnish  the  same 
rate  for  one  can  as  for  1,000  cans.  The  consequence  has  been  that 
the  large  dealers  forsook  Massachusetts  for  other  territory  to  the  injury 
of  the  farmers  of  the  State. 

The  Chamber  advises  the  abolishment  of  the  leased  car  system  and  the 
establishment  of  a  uniform  rate  for  milk  and  cream  per  can  based  on  a 
zone  or  flat  rate  per  mile,  the  railroads  performing  the  loading,  unload- 
ing, and  icing.  The  rate  for  milk  should  be  lower  than  that  for  cream. 
All  deductions  on  account  of  freight  train  service  should  be  abolished. 
The  rate  for  a  carload,  when  the  shipper  loads  at  not  more  than  two  sta- 
tions in  a  given  section  and  does  his  own  icing  and  unloading,  should  be 
at  a  percentage  less  than  the  per  can  rate.  Rates  should  be  uniform 
throughout  New  England,  thus  enabling  groups  of  farmers  to  ship  to  the 
market  at  an  equal  advantage  with  the  dealers,  or  to  secure  competitive 
bids  from  the  dealers.  This  system  is  substantially  the  same  as  that  pre- 
vailing on  the  Pennsylvania,  New  York  Central  and  Canadian  Pacific 
Railroads.  This  suggestion  of  the  Chamber  has  been  virtually  approved 
by  the  Interstate  Commerce  Commission  which  ruled  against  the  leased 
car  system. 

It  is  advised  that  State  and  local  boards  of  health  prohibit  the  ship- 
ment of  milk  and  cream  at  a  temperature  above  a  fixed  maximum  but  that 
railroads  should  not  be  expected  to  reduce  the  temperature  of  milk  and 
cream  in  transit.  The  establishment  of  country  milk  stations  it  is  held 
will  help  to  insure  the  shipment  of  milk  at  proper  temperature. 

In  1911,  the  Washington  Chamber  of  Commerce  investigated  the  milk 
situation  in  the  District  of  Columbia  and  among  other  things  attempted 
to  secure  information  that  would  permit  it  to  conclude  as  to  the  prac- 
ticability of  providing  refrigerator  car  service,  or  alternative  means,  for 
maintaining  milk  in  transit  at  below  50°F.  Of  the  railways  entering  the 
District  only  the  Pennsylvania  and  the  Southern  railways  and  the  New 
York  Central  and  Hudson  River  Railroad  Co.  heeded  the  requests  of  the 
Chamber  for  information. 

The  New  York  Central  lines  reported  that  the  cost  of  refrigeration 
varies  on  different  parts  of  the  system,  according  to  weather  conditions, 
the  kind  of  container  in  which  the  milk  is  shipped,  the  length  of  haul  and 
the  facilities  for  rapid  handling  at  destination. 

The  Pennsylvania  explained  that  three  factors  enter  into  the  cost  of 
hauling  milk  under  refrigeration,  to  wit,  the  length  of  haul,  the  tempera- 
ture of  the  milk  when  placed  in  the  car,  and  the  circumstance  whether  the 
cars  are  to  be  loaded  at  one  point  or  at  intervals  between  the  originating 
point  and  destination.  If  the  class  "Rf"  refrigerator  car  is  to  be  used 


214  CITY  MILK  SUPPLY 

for  the  purpose  proposed,  the  initial  icing  was  estimated  to  require 
7,400  Ib.  After  precooling  4,000  Ib.  of  ice  would  suffice  to  maintain  the 
milk  at  50°F.  for  a  distance  of  300  miles  or  a  24-hr,  run.  However,  if 
the  car  is  to  be  opened  at  different  points  to  receive  milk  the  temperature 
will  fluctuate  in  accordance  with  outside  conditions.  The  cost  of  icing 
a  car  with  12,000  Ib.  of  ice  will  approximate  $15  on  a  basis  of  $2.50  a 
ton  for  ice  and  including  necessary  labor.  By  using  the  same  cars  in 
the  milk  service,  the  bunkers  would  retain  a  percentage  of  the  ice  from 
one  trip  to  the  next  and  thus  the  car  would  require  on  the  same  basis 
as  above,  an  average  of  only  about  3,000  Ib.  of  ice  at  a  cost  of  $4.  Since 
the  necesary  space  for  loading,  and  the  requisite  amount  of  ice  must  be 
provided  from  the  starting  point  of  the  car  to  the  places  of  receiving  and 
discharging  its  load,  the  length  of  haul  does  not  materially  affect  the  cost. 

The  railways  transporting  milk  into  Washington  held  that  the  length 
of  haul  and  the  total  shipments  were  such  that  the  necessary  number  of 
refrigerator  cars  could  be  furnished  only  at  a  rate  which  would  make  the 
retail  price  of  milk  prohibitively  high. 

At  the  time  of  the  chamber's  investigation  the  Pennsylvania  lines 
carried  milk  into  Washington  from  less  than  30  miles  at  1%  cts.  per 
gallon ;  between  30  and  60  miles  at  2  cts. ;  over  60  and  not  over  90  at  2}^ 
cts.  Double  rates  were  charged  for  cream.  The  Southern  Railway 
carried  milk  at  a  flat  rate  of  2J^  cts.  a  gallon  which  included  the  return 
of  empty  receptacles. 

Improvement  in  Shipping  Milk  in  Pittsburgh. — In  1915  the  Depart- 
ment of  Public  Health  and  the  Chamber  of  Commerce  of  Pittsburgh  with 
other  civic  bodies  entered  into  negotiation  with  the  railroads  carrying 
milk  into  the  city  to  persuade  them  to  furnish  refrigerator  cars  for  the 
shipment  of  milk.  The  matter  was  finally  referred  to  the  Interstate 
Commerce  Commission  and  ultimately  with  the  aid  of  the  Bureau  of 
Chemistry  the  desired  improvement  was  obtained.  The  situation  was, 
that  while  part  of  the  milk  came  from  nearby  dairies,  part  came  from 
Ohio  and  was  in  transit  8  or  9  hr.  The  farmers  were  delivering  a  good 
article  at  the  railroad  stations  but  the  temperature  of  the  milk  in  baggage 
cars  ran  from  46°  to  73°F.,  with  most  of  it  well  above  65°.  In  many  cases 
the  temperature  of  the  milk  was  much  higher  than  it  was  at  the  way 
stations,  the  increase  being  sometimes  as  much  as  15°F.  The  bacterial 
counts  ran  as  high  as  22,800,000  per  cubic  centimeter  and  the  milk  was 
known  to  " geyser"  sometimes. 

The  railroads  pointed  out  that  with  the  milk  delivered  several  times 
a  day,  in  small  lots,  at  many  stations,  they  could  not  afford  to  supply 
refrigeration  and  had  to  handle  the  shipments  as  ordinary  baggage. 
Consolidation  of  the  shipments  so  that  carload  lots  could  be  quickly 
taken  aboard  was  essential  if  refrigeration  was  to  be  provided.  The 
wholesalers  agreed  to  furnish  consolidated  shipments  so  that  the  rail- 


THE  TRANSPORTATION  OF  MILK  215 

roads  would  have  only  one  or  two  pickups  and  those  were  to  be  of  im- 
portant quantities  and  the  farmers  agreed  to  deliver  milk  at  definite  hours. 
It  was  recognized  that  the  improved  service  made  an  increase  in  rates 
necessary  and  after  some  parleying  an  increase  of  20  per  cent,  was  agreed 
upon  and  approved  by  the  Interstate  Commerce  Commission.  When 
the  tariff  was  adopted  the  Pennsylvania  Railroad  was  ready  to  refrigerate 
7,000  gal.  a  day:  the  Baltimore  and  Ohio  promised  to  build  cars  to  care 
for  the  milk  between  Painesville  and  Akron ;  the  Lake  Shore  and  Michigan 
Southern  promised  to  operate  cars  between  Andover,  Ohio,  Oil  City, 
Pa.,  and  intermediate  stations,  while  the  Erie  and  the  Pennsylvania  and 
Lake  Erie  Railroads  agreed  to  care  for  the  milk  coming  over  their 
lines. 

Branch  lines  connect  the  surrounding  country  with  the  collecting 
centers  where  the  milk  will  be  picked  up  for  long  haul  to  Pittsburgh. 
Both  the  railroads  and  milk  dealers  are  building  large  ice  houses  in  the 
dairy  sections  to  store  ice.  Milk  is  now  being  received  in  Pittsburgh 
at  temperatures  not  above  48°F.  The  smaller  dealers  can  now  have  their 
milk  stay  in  the  refrigerator  cars  until  time  to  deliver  it  in  the  city,  whereas 
it  was  formerly  necessary  for  them  to  meet  the  trains  on  their  arrival  in 
Pittsburgh  between  10:00  p.m.  and  2:00  a.m.,  and  to  remove  the  milk 
to  the  milk  plants  and  refrigerate  it.  The  refrigerator  cars  thus  save 
rehandling  the  milk  and  are  said  to  effect  a  reduction  in  the  cost  of 
refrigeration  in  Pittsburgh  in  excess  of  the  added  rates. 

The  transportation  of  milk  by  common  carriers  is  a  phase  of  the  city 
milk  question  that  is  most  important  and  seems  likely  to  be  a  storm 
center  in  the  near  future.  It  is  important  to  the  dairy  farmers  that  they 
shall  have  a  railway  service  that  shall  get  their  milk  to  the  cities  in  prime 
condition,  and  at  reasonable  rates.  It  is  equally  important  that  the 
railway  service  shall  not  build  up  a  monopoly.  The  Boston  Chamber  of 
Commerce  has  pointed  out  the  evil  of  the  leased  car  system  and  it  is  held 
by  others  that  the  centralized  creamery  system  depends  for  its  existence 
on  low  rates  for  cream.  The  milk  of  many  cities  is  carelessly  handled 
and  improperly  refrigerated  on  its  way  to  the  city.  The  example  of 
Pittsburgh  where  organizations  of  the  citizens,  the  municipal  and  federal 
authorities  cooperated  in  conference  with  the  railroads  shows  how  the 
problem  must  be  met  and  augurs  well  for  its  solution. 

Temperatures  and  Age  of  Milk  Handled  by  Contractors. — In  the 
spring  of  1915  a  committee  of  the  International  Milk  Dealers'  Association 
sent  a  questionnaire  to  the  members  of  the  association  regarding  the 
temperature  and  age  of  the  milk  they  were  handling,  that  information 
might  be  obtained  which  would  be  useful  in  improving  milk  supplies. 
It  was  particularly  desired  to  elicit  information  as  to  conditions  that 
prevailed  during  July  and  August.  The  22  replies  that  were  returned 
have  been  summarized  in  Table  67.  The  committee  states  that  it  is 


21 

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THE  TRANSPORTATION  OF  MILK  217 

aware  that  many  of  the  figures  are  only  estimates  but  that  it  feels  that 
the  replies  as  a  whole  very  accurately  express  existing  conditions. 

Table  67  shows  that  milk  is  being  transported  and  delivered  at  too 
high  temperatures.  Bacterial  multiplication  proceeds  rapidly  at  tem- 
peratures above  50°F.  and  to  prevent  it,  milk  should  be  chilled  well  below 
that  point.  Yet,  the  average  temperature  of  the  milk  that  77  to  100 
per  cent,  of  the  dealers  were  accepting  from  their  producers  at  receiving 
stations,  railroad  stations,  milk  plants  and  aboard  train  in  the  country, 
was  above  50°F.  The  difference  between  the  average  temperature  of 
the  evening  and  morning  milk  delivered  by  the  producers  at  these  several 
places  ranged  from  4.1°  to  6.5°F.  and  indicates  that  the  morning  milk 
is  rushed  off  from  the  farm  without  the  benefit  of  the  thorough  cooling 
the  evening  milk  receives.  The  average  temperature  of  the  milk  that 
18  per  cent,  of  these  dealers  were  loading  onto  cars  at  country  receiving 
stations  was  above  50°F.  The  three  replies  from  country  bottling  plants 
indicate  that  the  milk  they  put  aboard  train  was  thoroughly  cooled  which 
undoubtedly  is  widely  true  of  these  plants.  The  average  temperature  of 
the  milk  of  69  per  cent,  of  the  dealers,  when  taken  from  the  cars  at  city 
railroad  stations,  of  75  per  cent.,  when  received  by  the  trucks  at  the  city 
railroad  stations  and  of  92  per  cent,  when  received  from  the  trucks  at 
city  milk  plants  was  above  50°F.  The  average  temperature  of  the  milk 
of  no  dealer  was  above  50°F.  when  loaded  onto  the  delivery  wagons  but 
that  of  28  per  cent,  of  the  dealers  was  above  this  temperature  when  de- 
livered to  customers. 

Use  of  Motor  Vehicles  in  Collecting  and  Delivering  Milk. — Motor 
vehicles  have  been  developed  to  a  stage  where  they  are  useful  for  certain 
purposes  in  the  dairy  industry,  namely,  for  the  collection  of  milk  and 
cream  in  the  dairy  districts  and  for  its  transportation  to  the  country 
milk  plants  or  to  the  railroad  stations,  and  in  the  cities  for  hauling  milk 
from  railway  terminals  to  the  city  milk  plants  and  thence  to  their  local 
distributing  branches.  They  are  also  used  in  the  cities  to  some  extent 
for  the  delivery  of  milk,  cream  and  condensed  milk  to  hospitals,  hotels, 
stores,  confectionary  establishments,  ice-cream  factories,  bakeries  and 
restaurants.  They  have  been  tried  for  regular  house-to-house  retail 
delivery  but  have  usually  failed  in  this  field  because  of  the  continual 
stopping  and  starting,  because  two  men  are  required  for  reasonable 
speedy  delivery  and  because  they  cannot  move  unattended  from  door  to 
door,  as  the  ordinary  intelligent  horse  does,  while  the  driver  is  delivering 
bottles.  However,  where  customers  live  at  some  distance  from  one  an- 
other, as  in  suburban  towns,  or  where  a  special  milk  such  as  a  modified 
milk  for  babies  is  being  delivered  over  an  area  of  considerable  size  and 
with  infrequent  stops,  even  in  retail  delivery  they  have  been  successful. 

Milk  is  shipped  to  the  city,  either  bottled  in  cases  or  in  cans.  The 
bottled  milk  on  arrival  is  ready  for  immediate  delivery  to  the  distributing 


218  CITY  MILK  SUPPLY 

stations  of  the  milk  companies  for  house-to-house  delivery  by  wagons,  or 
for  loading  directly  onto  the  delivery  wagons.  The  milk  that  arrives  in 
cans  has  to  be  carried  to  the  milk  plants,  often  for  pasteurizing  and  al- 
ways for  recanning  and  bottling.  Before  the  advent  of  the  motor  trucks 
the  best  location  for  the  milk  plants  was  near  the  terminals,  because 
the  milk  often  arrived  at  a  rather  high  temperature  and  so  needed 
prompt  cooling,  which  it  could  not  have  if  it  was  to  be  hauled  a  long  dis- 
tance by  horses  in  heavily  loaded  wagons  in  which  the  icing  of  the  cans 
was  impracticable.  The  location  of  the  plants  at  the  terminals  necessi- 
tates long  hauls  by  the  delivery  wagons,  and  by  the  wagons  that  carry 
cases  of  bottled  milk  to  the  branch  distributing  stations.  Bottled  milk 
in  cases  weighs  more  and  is  more  bulky  than  the  same  quantity  of  milk 
in  cans;  consequently  it  is  true  economy  to  plan  so  that  the  maximum  part 
of  the  distance  each  gallon  of  milk  is  carried,  shall  be  in  cans.  The  speed 
of  the  auto  truck  makes  it  feasible  to  locate  the  city  milk  plant  further 
from  the  railroad,  in  the  heart  of  the  retail  section  so  that  the  delivery 
wagons  which  carry  the  bulk  of  the  bottled  milk  shall  have  short  trips 
and  the  branch  delivery  stations  shall  be  conveniently  accessible.  There 
is  some  tendency  to  reconstruct  the  city  milk  business  along  these  lines 
but  heavy  investments  in  plants  at  the  terminals  make  readjustment 
slow.  In  city  use,  motor  trucks  have  demonstrated  their  superiority  to 
horse  traction  in  the  severe  storms  of  winter,  and  in  the  torrid  spells  in 
summer  when  the  horses  suffer  from  the  heat  and  traffic  becomes  slow 
and  unreliable. 

The  Commercial  Vehicle  in  1914  investigated  the  use  of  auto  trucks 
in  the  dairy  business  of  Greater  New  York  and  found  all  of  the  13  leading 
milk  companies  of  the  city  using  them;  these  concerns  had  59  trucks  in 
use.  There  were  fifteen  10-ton,  eight  6-  and  6j^-ton,  three  4J/£-ton, 
six  4-ton,  thirteen  3-ton,  two  2-ton,  six  l)^-ton  and  six  1-ton  vehicles. 
The  popularity  of  the  10-ton  truck  is  due  to  its  economy.  Motor  truck 
efficiency  depends  on  the  principle  that  the  larger  the  load  the  greater 
the  efficiency  provided  this  is  consistent  with  good  mileage  and  provided 
the  tonnage  can  be  carried  the  full  distance.  Some  of  the  lighter  trucks 
have  proved  unsuccessful,  for  the  loading  time  is  no  less  than  with  horses, 
so  that  in  the  limited  running  period,  the  truck  has  not  long  enough  to 
show  its  efficiency.  A  four-horse  team,  making  one  trip  per  night, 
hauls  more  cheaply  than  a  5-ton  truck  making  two  trips.  These  5-ton 
trucks  have  proved  profitable  in  distributing  to  outlying  delivery  depots 
to  which  three  trips  a  day  may  be  made  and  considerable  mileage  covered. 
Trucks  of  more  than  5  and  less  than  10  tons  capacity  were  profitable 
because  they  admit  of  more  rapid  handling  of  the  milk.  Light  trucks 
find  their  field  in  delivery  to  retail  stores,  in  distributing  condensed  milk 
and  in  special  deliveries.  These  light  vehicles  have  expanded  the  radius 
of  custom,  accelerated  the  speed  of  delivery,  cut  down  the  number  of 


THE  TRANSPORTATION  OF  MILK  219 

vehicles  employed,  thereby  decreasing  the  loading  time  and  congestion, 
and  have  decreased  the  cost  of  delivery. 

In  general,  the  mode  of  operation  is  to  use  the  10-ton  trucks  for  trans- 
ferring the  bulk,  and  less  often  the  cased  milk  from  the  trains  to  the  main 
city  milk  plant,  for  carrying  the  cased  milk  from  the  main  plant  to  the 
local  delivery  plants  and  for  returning  the  empty  utensils  to  the  railway 
terminal.  The  medium-sized  trucks  are  used  less  for  the  traffic  between 
the  terminals  and  the  main  plant,  but  more  for  that  between  the  main 
plant  and  the  local  ones,  and  for  delivery  to  hospitals,  restaurants,  con- 
fectionery establishments  and  stores  that  take  good-sized  orders  of  milk 
and  that  are  considerable  distance  apart.  The  1  to  2-ton  trucks  are 
used  chiefly  in  special  service. 

The  10-ton  trucks  are  of  two  sorts,  regular  motor  trucks,  and  tractors 
that  couple  onto  trailers,  the  latter  having  the  advantage  that  on  delivery 
of  the  load  they  can  uncouple  at  once  and  couple  up  to  other  trailers, 
thereby  saving  time  that  the  regular  trucks  lose  in  waiting  to  be  unloaded 
and  loaded  again.  The  large  trucks  leave  the  garage  early  in  the  evening 
and  go  to  the  main  and  local  plants  for  loads  of  utensils  which  they  carry 
to  the  railway  terminals  and  return  therefrom  with  a  load  of  milk,  as  a 
rule  making  two  trips  in  a  night  which  work  is  usually  finished  by  six  in 
the  morning.  In  the  day  time  these  trucks  are  in  service  between  the 
main  and  local  plants. 

The  itinerary  of  a  tractor  and  10-ton  trailer  engaged  in  hauling  milk 
from  railway  terminal  to  the  main  plant  and  of  part  of  the  itinerary  of  a 
4-ton  motor  truck  employed  in  distribution  to  stores  appears  in  Tables  68 
and  69. 

There  is  marked  difference  in  the  efficiency  with  which  the  several 
trucks  studied  were  operated  and  this  is  set  forth  in  Table  70  which  is  self- 
explanatory.  However,  attention  is  called  to  the  fact  that  the  average 
commercial  ton- miles  made  by  the  Howell-Demarset  truck  show  that  it 
was  engaged  in  a  different  sort  of  traffic  than  the  others.  Table  71  shows 
the  waste  factor  of  standing  time  for  the  several  trucks. 


220 


CITY  MILK  SUPPLY 


LK  Co.'s  KNOX-MARTIN  TRACTOR,  MAY  5-6,  19141 

c  —  hauling  raw  milk  from  Jersey  City  terminals  to  Brooklyn  pas- 
plant, 
ips  —  two. 
Brooklyn  pasteurizing  plant  at  942  De  Kalb  Avenue  to  Erie  freight 
in  Jersey  City,  N.  J.,  via  Williamsburgh  Bridge  and  Chambers 

ry. 

Incident 

Leave  garage  . 
Stop  to  light  lamps. 
Start. 
Arrive  at  pasteurizing  plant,  couple,  with  trailer  loaded  with  185 
empty  milk  cans;  change  tail  light  and  rear  number;  wait  for  helper 
to  get  ferry  money. 
Leave. 
Arrive  at  ferry  gate. 
Leave  ferry. 
Arrive,  start  to  unload  empty  cans. 
Unloaded,  maneuver  to  loading  platform. 
Train  not  in,  leave  for  supper. 
Return  from  supper,  wait  for  train. 
Start  loading. 
Loaded  with  185  cans,  start  icing. 
Leave. 
Arrive  at  ferry  gate. 
Leave  ferry. 
Arrive  pasteurizing  plant,  uncouple  full  trailer;  couple  on  to  trailer 
loaded  with  empties;  change  tail  light  and  rear  number. 
Leave. 

Arrive  at  ferry  gate,  missed  12:15  ^erry. 
Leave  ferry. 
Arrive,  start  to  unload  empty  cans. 
Unloaded,  maneuver  to  loading  platform. 
Start  loading  185  cans  of  milk. 
Loaded,  leave. 
Arrive  at  ferry  gate,  side-track  for  horses,  last  in. 
Leave  ferry. 
Arrive  pasteurizing  plant,  uncouple  trailer,  change  tail  light  and  rear 
number. 
Run  into  street;  breakfast. 
Leave. 
Arrive  garage. 

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THE  TRANSPORTATION  OF  MILK 


221 


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222 


CITY  MILK  SUPPLY 


TABLE   70.— COMPARISON  OF  THE  OPERATION  OF  AUTO  TRUCKS   (The  Commercial 

Vehicle,  1914) 


;  "3 

J 

M-J* 

•S-A3 

—  35— 

_a 

s 

If 

"a 

I 

1 

II"2 

i 

1 

fl^ 

1 

01    M 

to 

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1 

<*J 

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<D   S 

. 

&  S 

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d 

M^ 
o«  c3 
If 

P 

|s 

1 

o|-| 

1 

i 

^! 

4a 

II 

1 

ll.sl 

& 

|| 

Borden's  Knox-Martin  tractor  with  10-ton  trailer.  

152.8 

2.7 

5.9 

33.5 

45 

45 

55 

Empire  State  Dairy  Go's.  5-ton  Garford  tractor  with  10-ton 

145.5 

2.4 

8.3 

29.2 

52 

35 

65 

trailer. 

Slawson-Decker's  10-ton  Hewitt  truck 

126.2 

1.9 

5.6 

29  3 

7S 

qq 

fi7 

Empire  State's  5-ton  Garford  truck  

171.6 

5.7 

10.5 

[5  0 

7fi 

Oo 

E7 

O/ 

Howell-Demarset's  4-ton  Peerless  truck  

27.0 

3.3 

9.9 

57.7 

*  o 
50 

O/ 

33 

67 

TABLE  71 


-WASTE  FACTOR  OF  STANDING  TIME  FOR  SEVERAL  DAIRY  TRUCKS  (The 
Commercial  Vehicle,  1914) 


Per  cent., 

Per  cent., 

Per  cent., 

loading 

unloading 

waste 

time 

time 

time 

Borden's  tractor  with  10-ton  trailer                                          31 

14 

KK 

Empire  State  Dairy  Co.'s  tractor  with  10-ton  trailer  .  .  .        34 

18 

48 

Slawson-Decker's  10-ton  truck  34 

44 

22 

Empire  State's  5-ton  truck  33 

43 

24 

Howell-Demarset's  4-ton  truck  26 

24 

50 

In  a  small  way  the  motor  cycle  has  been  utilized  for  carrying  milk  and 
cream  and  it  is  possible  that  in  the  future  it  may  be  of  considerable  help 
to  small  dairymen. 

The  cost  of  operation  of  motor  vehicles  in  dairy  traction,  is  of  course, 
very  variable;  the  items  that  make  it  up  may  be  gleaned  from  Fender 
and  Thompson's  estimate  of  the  costs  of  operating  a  3^-ton  draft  beer 
delivery  truck  and  from  Thompson's  estimates  on  two  10,000-lb.  brewery 
trucks  (Tables  72  and  73). 


THE  TRANSPORTATION  OF  MILK 


223 


TABLE  72. — ESTIMATES  OF  COST  OF  OPERATING  A  3.5-TON  DRAFT  BEER  DELIVERY 
TRUCK  (FENDER  AND  THOMPSON) 


Average  maximum  load  in  pounds,  approxi- 
mately   
Miles  per  trip  



7000.0 
14  0 

Calls  per  mile  

0  7 

Hours  per  trip  for  loading  and  unloading..  .  . 
Hours  working  per  day  

8.0 
9  0 

Average  running  speed  in  m.p.h.  
Hours  per  trip  standing  

7,900-lb. 
electric 
7.0 
2  1 

7,000-lb. 
gasolene 
8.5 
2  1 

Two-horse  wagon 
(two  extra  horses) 
4.0 
2  1 

Houss  per  trip  moving  
Hours  per  trip  total 

2.0 
4  1 

1.7 
3  8 

3.5 
5  6 

Average  number  of  trips  per  9-hr,  day  
Miles  per  day.  .  .  . 

2.2 
31  0 

2.4 
33  0 

1.6 
22  0 

Calls  per  day  '.  .  .  .  . 
Days  used  per  year  
Vehicle-miles  per  year  
Calls  per  year  

22.0 
285.0 
8,850.0 
6  200  0 

23.0 
270.0 
8,900.0 
6  230  0 

15.0 
285.0 
6,250.0 
4  370  0 

Expense  per  year  : 
Tires  or  shoeing.  . 

1330  00 

$380  00 

$144  00 

Repairs  . 

300  00 

625  00 

12*1  00 

Battery  
Veterinary  
Lubricants  

360.00 
15  00 

60  00 

24.00 

Electricity  at  3  cts.  per  kw.-hr  ... 
Gasolene  at  16  cts.  per  gal  
Feed  
Garage  or  stable  
Driver  and  helper 

265.00 

240.00 
1  210  00 

350.00 

240.00 
1  280  00 

760.00 
280.00 
1  210  00 

Depreciation 

290  00 

610  00 

2^0  00 

Interest  

102  "00 

120  00 

38  00 

Insurance 

140  00 

180  00 

QK    00 

Total  annual  expense 

3  252  00 

3  854  00 

2  866  00 

Cost  per  day  
Cost  per  mile. 

$11.40 
0  39 

$14.25 
0  43 

$10.00 
0  46 

Cost  ner  call.  . 

0.52 

0  62 

0  66 

224 


CITY  MILK  SUPPLY 


TABLE  73. — DATA  ON  GASOLENE-VEHICLE  OPERATION  (THOMPSON) 
(5-ton  wholesale  delivery  trucks) 


General  Information: 
Business                                 

Brewery 

Brewery 

Class  of  service                           

Heavy  trade 

Wholesale  delivery 

Rating  of  trucks  pounds 

10,000 

10,000 

Number  of  trucks         

1 

1 

First  cost,  dollars  per  truck  
Age  of  truck  at  time  of  report,  months 

4,800 
10 

'  5,100 
12 

IVtonths  covered  by  report 

10 

12 

Kind  of  tires                            

Solid 

Solid 

Nature  of  roads                                              

Good 

Excellent 

Nature  of  grades 

Flat 

Rolling 

Performance  : 
Miles  per  annum                                    

8,870 

11,700 

Days  used  per  annum 

292 

294 

Miles  per  day  used.              

30 

40 

Pounds  hauled  per  day                                      .... 

6,500 

IVIiles  covered  per  gallon  of  gasolene 

4  13 

4  65 

Operation  and  maintenance: 
Gasolene  cents  per  gallon                             

9.5 

14.0(a) 

Lubricants  dollars  per  annum 

33 

118 

Tire  renewals  dollars  per  annum  

541 

941 

Repairs  dollars  per  annum                                   .  . 

244 

410 

Painting  dollars  per  annum 

77 

Lubricants  cents  per  mile                 

0.4 

1.0 

Gasolene  cents  per  mile 

2.3 

3.0 

Tire  renewals,  cents  per  mile  

6.1 

8.0 

Repairs  and  painting                                   

2.7 

3.5 

Garage  rent,  garage  labor  and  general  expense.  .  .  . 
Driver                             

938 

180 
1,090 

Helper                                                                

726 

960 

Overhead  charges: 
\mortization   dollars  per  annum  

284 

548 

Interest                                                            

291 

153 

Fire  and  liabilitv  insurance 

102 

231   i 

(a)  Average  price  for  the  period  approximate. 

Age  of  Milk  When  Delivered  to  Consumers. — The  time  that  elapses 
between  the  milking  of  the  cows  and  the  delivery  of  the  milk  to  the  con- 
sumer is  a  matter  of  importance.  It  varies  greatly  in  the  different  cities 
for  some  like  Baltimore,  Chicago  and  Milwaukee  fortunately  draw  their 
milk  supplies  from  producing  regions  but  a  few  hours  distant,  whereas 
Boston  gets  much  of  its  supply  from  Canada,  Maine  and  Vermont  while 
milk  comes  into  New  York  City  from  points  400  miles  distant.  Table 
74  summarizes  information  supplied  by  22  dealers  of  the  International 
Milk  Dealer's  Association  in  regard  to  milk  in  transit  to  them  in  three 
Provinces  and  13  States.  Some  of  the  interesting  points  brought  out 
are,  that  on  the  average  the  morning  milk  handled  by  these  dealers  re- 


THE  TRANSPORTATION  OF  MILK 


225 


rnained  in  the  farmers  possession  2J£  hr.,  the  night  12  hr.;  that  the  milk 
was  held  in  the  country  receiving  stations  and  bottling  plants  5J^  to 
6J^  hr.;  that  it  was  4)4  hr.  on  the  cars  en  route  to  the  city;  that  it  was 
held  in  the  city  milk  plants  16J4  nr-i  and  that  the  morning's  milk  was 
31  and  the  night's  40  hr.  old  when  delivered  to  the  consumers. 


TABLE  74. — NUMBER  OF  HOURS  MILK  is  HELD  IN  STAGES  OF  ITS  JOURNEY  FROM 

FARM  TO  CONSUMER.     PREPARED  FROM  REPORT  OF  THE  INTERNATIONAL  MILK 

DEALERS'  ASSOCIATION 


1     W 

*o  b 

«*H     ^ 

• 

•a 

2 

3 

IP 

ij 

11 

ill 

fc£ 

1 

h 

11 

•§•0 
Ifi 

•8 

Sto  * 

a|fc 

8  °  S 

'i*s  s 

P   M 

a  o 

** 

M£^ 

I  *"» 

Sfe^ 

a>  §* 

^^  £ 

•§'£ 
|| 

111 

<!  a  a 

I  r§ 

C8  3  0 

<<3  o  a 

&A  O 

111 

in 

22« 

111 

In  farmer's  possession  after  milking: 

Night  milk     . 

22 

36 

15.1 

M 

9.2 

12.1 

Morning  milk 

20 

24 

5.6 

M 

1.0 

2.5 

Remaining  at  country  receiving  stations.  .  . 

11 

24 

11.6 

2.2 

5.5 

Remaining  at  country  bottling  plants: 

Night 

1 

3 

3 

3.0 

Morning 

2 

12 

8.6 

1 

4.6 

6.6 

Remaining  at  country  railroad  stations  from 

delivery  by  farmers  till  loaded  on  cars.  . 

11 

2 

1.7 

0 

0.3 

0.7 

Remaining  in  railroad  cars        .    .    . 

19 

24 

7.2 

M 

1.9 

4.3 

Hours  elapsing  between  removal  from  cars 

and  arrival  at  city  milk  plant      .    . 

19 

4 

1.4 

M 

0.5 

1.0 

Hours  between  arrival  at  city  milk  plant  and 

loading  onto  city  delivery  wagons  

21 

48 

22.5 

0 

10.1 

16.3 

Hours  on  city  delivery  wagons  

21 

14 

8.2 

1  14 

1.9 

4.6 

Total  age  of  milk  when  delivered  to  con- 

' 

sumers: 

Night  

16 

84 

53.2 

2J4 

28.4 

40.3 

Morning       

17 

84 

41.9 

18.7 

31.2 

Cost  of  Operating  Delivery  Wagons. — The  cost  of  operation  of 
delivery  wagons  varies  greatly  in  different  localities.  The  data  collected 
by  Thompson  as  given  in  Table  75  show  how  this  cost  is  reckoned. 


226 


CITY  MILK  SUPPLY 


TABLE  75. — DATA  ON  HORSE-VEHICLE  OPERATION  (THOMPSON  ): 


General  Information: 

Business 

Number  of  one-horse  wagons 

Number  of  two-horse  wagons 

Average  number  of  horses 

Percentage  of  extra  horses 

First  cost  of  one-horse  wagon,  dollars 

First  cost  of  two-horse  wagon,  dollars '. 

Average  price  paid  for  horses 

First  cost  per  set  of  harness 

Performance : 

Miles  traveled  per  day 

Trips  per  wagon  per  day 

Deliveries  per  wagon  per  day 

Pounds  hauled  per  wagon  per  day 

Operation  and  maintenance: 

Shoeing  dollars  per  annum,  per  horse 

Veterinary  dollars  per  annum,  per  horse ^  .  . 

Feed . .- .  . 

Stable  rent,  stable  labor  and  general  expense,  dollars  per  annum, 
per  horse 

Wagon  repairs  and  painting,  per  wagon 

Harness  repairs,  per  wagon 

Driver,  per  wagon 

Overhead  charges: 

Interest  and  amortization,  dollars  per  annum,  per  horse 

Interest  and  amortization,  single  wagon,  dollars  per  annum,  per 
wagon 

Interest  and  amortization  double  wagon,  dollars  per  annum, 

per  wagon. 
Total  per  annum  dollars: 

Operation  per  horse 

Maintenance  per  wagon 


Milk 

1,234 

237 

1,983 

16 

225 

225 

225 

25 

8 
1 

225 
2,000 

21 

3 

180 

50 

100 

5 

780 

34 

38 
38 


254 
105 


Milk    Milk 
62         11 

8 

86 

10 

275 

500 

250 


1 

14 
8 

235 
235 
225 


45         50 


20 

1 

150 


12 

1 

250 


1,800  12,000 


20  !      24 

3 
168 

82 

86 

12 

776 

25 

48 
82 


273 

98 


3 
180 

82 

28 

1 

780 

14 

17 
17 


289 
29 


1  From  "Relative  Fields  of  Horse,  Electric  and  Gasolene  Trucks,"  Res.  Bull.  4, 
Dept.  Elect.  Eng.,  Mass.  Inst.  Tech.,  1914. 

Sources 

VAN  ALYSTYNE,  "The  Country  Milk  Situation  in  New  York  State,"  Butt.  54,  N.  Y. 

Dept.  Ag.,  December,  1915. 
HOPPER  and  ROBERTSON,  "The  Cost  of  Milk  Production,"  Bull  357,  Cornell  Univ. 

Ag.  Expt.  Sta.,  1915. 
THOMAS,  "A  Review  of  Practical  Methods  for  Supervising  the  Milk  Supply  of  Cities," 

Jour.  Am.  Public  Health  Assn.,  vol.  1,  No.  11,  pp.  798-807,  1911. 
ZIPPEL,   "The  Transportation  and  Care  of  Milk  by  Railroad  Companies,"  Proc., 

Conference  on  Milk  and  Milk  Problems,  N.  Y.  Milk  Committee,  December,  1910. 
SHARWELL,  "Lessons  to  be  Learned  from  an  Inspection  that  Follows  Milk  from  the  Cow 

to  the  Consumer,"  4th  Annual  Report  of  the  International  Association  of  Dairy 

and  Milk  Inspectors,  1915. 
BOWEN,    "The  Application  of  Refrigeration  to  the  Handling  of  Milk,"  Butt.  98, 

U.  S.  Dept.  Ag. 


THE  TRANSPORTATION  OF  MILK  227 

WILLIGE,  "  Report  of  Washington  Chamber  of  Commerce  on  the  Milk  Situation  on  the 
District  of  Columbia,"  Sen.  Doc.  863,  61st.  Cong.,  Third  Session. 

Boston  Chamber  of  Commerce,  "Investigation  and  Analysis  of  the  Production, 
Transportation,  Inspection  and  Distribution  of  Milk  and  Cream  in  New  Eng- 
land," July,  1915. 

WHITAKER,  "The  Milk  Supply  of  Boston  and  Other  New  England  Cities,"  Bull.  20, 
Bureau  Animal  Industry,  U.  S.  Dept.  Ag.,  1898. 

WHITAKER,  "The  Milk  Supply  of  Boston,  New  York  and  Philadelphia,"  Bull.  81, 
Bureau  Animal  Industry,  U.  S.  Dept.  Ag.,  1895. 

MERRITT,  "The  Production  and  Consumption  of  Dairy  Products,"  Bull.  177,  U.  S. 
Dept.  Ag.,  1915. 

GUNN,  Bull,  of  the  Milwaukee  Bureau  of  Economy  and  Efficiency,  No.  13,  Health 
Dept.  1,  "Milk  Supply." 

The  Commercial  Vehicle,  a  series  of  articles  on  motor  vehicles  and  the  dairy  business 
in  the  issues  of  May  15,  June  1,  June  15,  and  July  1,  1914. 

PENDER  and  THOMPSON,  "Observations  on  Horse  and  Motor  Trucking,"  Vehicle  Res. 
Bull.  3,  Dept.  Elect.  Eng.,  Mass.  Inst.  Tech. 

THOMSON,  "Relative  Fields  of  Horse,  Electric  arid  Gasolene  Trucks,"  Vehicle  Res.  Bull. 
4,  Dept.  Elect.  Eng.,  Mass.  Inst.  Tech.,  1914. 

BURCH,  "The  White  Whirlpool,"  Farm  and  Fireside,  Feb.  28,  1914. 

WARREN,  "Farm  Management." 

SHELDON,  "Dairying,"  1912. 

Creamery  and  Milk  Plant  Monthly,  vol.  3,  No.  5,  Jan.  15,  "An  Account  of  the  Improved 
Railway  Milk  Service  in  Pittsburgh." 

HARBISON,  "Transportation  of  Milk  and  Cream,"  The  Creamery  and  Milk  Plant 
Monthly,  vol.  3,  No.  12,  August,  pp.  11-12,  1915. 

GAMBLE,  "Importance  of  Cooling  Milk,"  Hoards  Dairyman,  Sept.  5,  1913. 

Report  of  Committee  appointed  by  the  International  Milk  Dealers'  Association  to 
Cooperate  with  the  Official  Dairy  Instructors'  Association  on  the  "Improve- 
ment of  Milk  Supplies,"  1915. 


CHAPTER  VI 
THE  MILK  CONTRACTOR 

Advent  of  the  City  Milk  Problem. — Dairying  is  one  of  the  oldest 
arts  of  the  human  race.  It  is  not  known  when  man  began  to  keep 
milk-giving  animals  but  records  show  that  dairying  was  practised 
in  India  1,500  years  and  in  Egypt  2,000  years  before  Christ.  Like  the 
origin  of  dairying  itself,  that  of  the  problem  of  public  milk  supply  is  lost 
in  antiquity.  It  is  conceivable  that  as  long  as  man  led  a  nomadic  life 
the  art  did  not  exist  but  it  must  have  appeared  soon  after  he  established 
fixed  abodes  and  have  become  pressingly  important  wherever  he  built 
large  cities.  The  complexity  of  the  question  has  increased  apace  with 
advancing  civilization  till  in  modern  times  its  solution  severely  tests  man's 
highest  abilities  and  involves  large  amounts  of  capital.  In  the  United 
States  the  transition  from  rural  to  urban  communities  was  rapid,  conse- 
quently the  problem  of  city  milk  supply  suddenly  loomed  large  so  that 
Americans  are  apt  to  think  it  new,  whereas  it  is  very  old. 

Though  the  change  has  come  quietly,  it  has  been  a  matter  of  years 
and  though  our  oldest  cities  have  been  struggling  with  the  problem  since 
the  middle  of  the  last  century  and  even  earlier,  in  its  modern  aspect  it 
has  forced  itself  to  the  front  only  within  the  last  25  years,  so  that  it  belongs 
peculiarly  to  the  present  generation.  It  is  easy  to  trace  its  development. 

In  small  country  towns  most  families  have  their  own  cows;  those  that 
do  not  depend  on  a  neighbor  for  their  milk  supply,  as  a  rule  calling  at  the 
farm  for  their  milk.  There  is  no  milkman  and  the  amount  of  milk  that 
can  be  purchased  is  very  limited.  Indeed  summer  visitors  and  others, 
in  such  places,  often  experience  considerable  difficulty  in  getting  milk 
at  all.  As  these  villages  grow,  the  demand  for  milk  becomes  large  enough 
to  encourage  some  farmer  to  embark  in  the  milk  business.  As  trade 
increases,  he  finds  that  he  cannot  raise  enough  milk  and  buys  of  other 
farmers.  Thus  in  embryo  the  milk  contractor  appears,  and  some  of  the 
evils  of  contracting  begin,  for  the  milkman  rarely  has  any  control  over 
the  farmer  and  the  latter  seldom  gets  enough  for  his  milk  to  encourage 
him  either  to  improve  the  conditions  under  which  it  is  produced  or  to 
take  special  care  of  it.  Such  as  it  is,  it  is  accepted  as  the  best  obtainable 
by  the  milkman,  but  it  is  very  apt  to  be  disposed  of  to  the  customers  who 
take  little  milk  and  to  those  who  are  poor  pay.  The  growth  of  the  village 
into  a  town  or  small  city  increases  the  demand  for  milk  and  the  success 
of  the  one  milkman  tempts  others  to  start  in  the  business.  It  may  be 

228 


THE  MILK  CONTRACTOR  229 

overdone,  which  invites  sharp  practice  such  as  watering  and  skimming 
of  the  milk,  and  there  very  likely  follows  a  period  of  uncertain  develop- 
ment. Routes  change  owners  in  quick  succession;  it  is  a  time  of  in-and- 
outers,  for  farmers  peddle  milk  when  prices  are  good  and  quit  to  carry  their 
milk  to  a  creamery  when  they  are  bad.  At  this  stage  the  milk-consum- 
ing public  suffers;  it  is  a  period  of  poor  milk  and  unreliable  service. 
Nevertheless  a  few  milkmen  succeed  in  establishing  a  reputation  and  in 
convincing  people  that  they  have  the  intelligence  and  capital  to  succeed. 
They  absorb  the  trade  of  the  weaker  dealers  and  carry  on  the  bulk  of  the 
business,  supplying  the  city  with  milk  from  their  own  farms  and  those 
of  their  neighbors  in  the  city  and  its  environs.  Gradually  the  farms 
within  the  corporate  limits  of  the  city  give  way  to  city  blocks  and  land 
in  the  suburbs  becomes  so  high-priced  that  it  cannot  be  profitably  farmed, 
so  that  the  milk  supply  comes  from  further  and  further  away,  till  at  last 
it  is  no  longer  within  wagon  haul,  and  the  intimate  relationship  that 
existed  in  the  village  between  the  dairy  farmer  and  the  consumer  is  lost. 
By  whom  the  milk  is  produced  and  whence  it  comes,  the  city  man  does 
not  know.  His  milkman  is  one  who  buys  the  milk  at  wholesale  from  the 
dairyman  and  retails  it  to  the  consumer.  This  newcomer  is  known  as 
the.  middleman,  city  milkman,  or  contractor. 

The  Milk  Contractor. — His  advent  comes  about  naturally  and  for 
several  reasons.  Dairy  farming  is  a  business  in  itself  and  requires  all 
the  time,  thought  and  energy  the  man  who  carries  it  on  has.  Likewise 
the  selling  of  milk  is  a  business  complete  in  itself  and  the  creation  and. 
maintenance  of  an  organization  competent  to  render  the  prompt  and 
reliable  service  necessary  for  the  city  man  to  deal  understandingly  with 
him  and  to  collect  payment  for  service  rendered,  can  hardly  be  well 
done  by  one  absorbed  in  the  problems  of  production.  Also,  the  handling 
of  the  milk  on  its'  arrival  in  the  city,  preparatory  to  delivery,  requires 
knowledge  and  training  not  possessed  by  the  farmer.  Finally,  the  separa- 
tion of  the  city  milk  trade  from  that  of  milk  production  effects  a  division 
of  capital  so  that  the  burden  of  financing  the  business  falls  less  heavily 
on  both  producers  and  retailers,  and  in  the  country  makes  it  possible  for 
men  to  engage  in  dairying  who  could  not  do  so  if  they  had  to  pay  for  the 
shipment  of  milk  to  the  city  and  in  any  large  measure  be  responsible  for 
it  there.  In  fact  in  the  early  days  before  the  city  milk  business  became 
stable,  severe  losses  were  suffered  by  dairymen  who  not  rarely  sold  milk 
to  men  who  had  not  sufficient  capital  and  so  failed,  leaving  the  farmer 
in  the  lurch  with  a  large  amount  of  money  due  him  and  no  market  for 
his  milk  till  he  could  find  a  new  contractor  to  handle  it. 

The  contractor,  then,  is  the  middleman  who  in  building  his  own 
business  has  made  himself  all  but  indispensable  to  both  the  milk  consumer 
and  milk  producer.  To  the  consumer,  the  contractor  must  deliver  clean 
wholesome  milk  in  order  to  win  his  trade  and  hold  it.  The  city  man  is 


230  CITY  MILK  SUPPLY 

usually  ignorant  of  the  methods  that  are  in  use  to  protect  the  milk  supply 
and  of  the  value  of  milk  as  a  food.  So  it  is  good  policy  for  the  dealer  to 
become  his  mentor  and  interest  him  in  both.  It  is  common  for  dealers 
to  take  this  attitude  and  deliver  illustrated  lectures  before  church  societies 
and  women's  clubs,  explaining  the  dairy  business  from  the  farm  to  the 
consumers'  door.  Advertising  literature  is  distributed,  telling  the  merits 
of  the  several  brands  of  milk  handled  by  the  dealer,  setting  forth  the 
food  value  of  milk  and  telling  how  to  care  for  it.  Often  clubs  of  various 
sort  are  entertained  at  the  city  milk  plant,  which  they  inspect  and  after- 
ward listen  to  a  talk  on  milk  and  are  served  a  luncheon  of  dairy  products 
dealt  in  by  their  hosts.  Occasionally  trips  may  be  conducted  to  the 
farms.  By  such  methods  suspicion  is  laid  and  in  its  place  hearty  con- 
fidence in  dairying  and  dairy  products  established.  Such  work  is  expen- 
sive but  necessary.  It  is  an  element  in  the  cost  of  carrying  on  the  milk 
business  that  the  dairy  farmer  rarely  thinks  of  but  one  from  which  he 
reaps  profit  for  it  stimulates  the  use  of  milk. 

The  relations  between  the  farmer  and  the  city  milkman  is  delicate. 
Neither  can  thrive  at  the  expense  of  the  other  and  yet  the  one  is  interested 
in  getting  the  best  possible  price  for  his  milk,  and  the  other  in  purchasing 
it  at  the  lowest  figure.  If  conditions  are  such  that  the  contractor  can 
and  does  squeeze  the  farmer,  the  latter  will  produce  a  low-grade  milk  and 
in  addition  be  disgruntled  and  antagonistic  to  the  contractor  and  'finally, 
if  he  becomes  convinced  that  there  is  no  money  in  dairying,  will  sell 
his  cows  and  take  up  other  lines  of  farming.  On  the  other  hand,  if  the 
dairy  farmers  by  combination  and  agreement  are  able  to  withhold  milk 
from  the  market  long  enough  to  wring  high  prices  from  the  contractor 
his  profits  are  materially  lessened,  for  he  is  generally  loth  to  raise  prices 
to  the  consumer  because  there  usually  results  a  great  outcry  against  his 
supposed  greed  and  there  is  also  likely  to  be  a  decreased  consumption  of 
milk  for  the  wages  of  city  folk  are  for  the  most  part  fixed  and  they  are 
both  unable  and  unwilling  to  pay  more  for  milk.  Moreover,  a  principal 
reason  that  milk  is  so  widely  used  is  that  it  offers  good  food  value  cheap 
and  raising  its  price  brings  it  into  competition  with  other  foods  and 
consequently  encourages  people  to  use  them.  The  price  of  milk  is 
fixed  primarily  on  the  ability  and  willingness  of  the  city  man  to  pay  for 
it.  Out  of  his  demand  grows  the  competition  for  the  farmer's  milk. 

Different  Branches  of  Dairying  Dominate  Producing  Territory. — Milk  is 
wanted  for  dairy  manufactures  and  for  city  milk ;  the  products  of  the  former 
are  butter,  cheese,  condensed  milk,  milk  powder  and  ice  cream  and  as  the 
latter  it  is  consumed  in  its  natural  state  and  as  specially  prepared  bever- 
ages. It  follows  that  there  is  competition  for  dairy  territory  between 
cheese  factories,  creameries,  condenseries  and  city  milk  plants.  Usually 
cheese  makers  pay  least  for  milk  so  that  the  cheese  industry  is,  broadly 
speaking,  built  up  in  new  dairy  territory,  or  that  which  is  located  too  far 


THE  MILK  CONTRACTOR  231 

from  a  large  city  to  supply  the  city  milk  trade,  or  where  railroad  facilities 
are  undeveloped,  or  transportation  rates  unfavorable  for  creameries  and 
condenseries.  Creameries  pay  more  for  milk  than  cheese  factories  but 
usually  less  than  condenseries,  so  that  it  is  often  possible  for  the  latter  to 
convert  creamery  territory  to  their  use.  City  milk  dealers  pay  most  for 
milk  and  the  growth  of  cities  compels  them  to  reach  out  further  and 
further  for  it,  consequently  they  capture  dairy  districts  that  formerly 
supplied  the  dairy  manufacturers.  Each  business  has  its  peculiar  needs 
and  dairying  takes  on  character  in  accordance  with  them,  the  purchaser 
in  each  case  being  the  power  that  shapes  the  development  of  the  territory. 

Influence  of  Contractors  in  Dairy  Districts. — The  influence  of  dealers 
who  buy  milk  from  a  few  farms  is  small,  even  though  the  entire  dairy 
business  of  the  country  round  consists  in  supplying  such  men.  So  also, 
is  that  of  a  class  of  wholesalers  who  supply  an  inferior  grade  of  milk  to 
•cities  having  weak  or  badly  enforced  milk  ordinances,  for  these  men 
succeed  by  picking  up  any  and  all  sorts  of  milk  at  the  lowest  prices  and 
bother  little  about  the  development  of  the  country  so  long  as  it  produces 
the  milk  they  need.  Dealers  who  are  in  the  business  in  a  larger  way  have 
it  within  their  power  to  lead  the  communities  in  which  they  operate  into 
the  paths  of  sound  dairying  and  some  of  them  do  so,  but  most  fail  to  keep 
in  intimate  contact  with  their  producers  and  are  surprisingly  indifferent 
and  ignorant  as  to  conditions  in  the  dairy  country  on  which  they  are 
dependent.  These  men  are  satisfied  to  rely  on  the  inspections  of  boards 
of  health  to  maintain  proper  sanitary  conditions,  and  do  not  perceive 
the  advantages  of  supplementing  such  inspection,  by  the  efforts  of  men 
in  their  own  employ  who  will  keep  them  accurately  informed  as  to  the 
conditions  under  which  the  milk  they  are  buying  and  for  the  quality  of 
which  they  are  responsible  is  produced,  who  also,  will  have  an  educative 
influence,  and  who  may  be  expected  to  establish  cordial  relations  between 
dealers  and  producers.  The  large  dairy  companies  are  doing  the  best 
work  for  the  producers.  They  have  inspectors  who  instruct  the  dairy- 
men in  animal  breeding  and  in  the  feeding  and  management  of  herds  and 
who  earnestly  endeavor  to  establish  good  feeling  between  the  farmer  and 
the  companies  by  helping  each  to  an  understanding  of  the  others  diffi- 
culties. These  inspectors  employed  by  the  companies  are  in  a  position 
to  win  the  confidence  of  the  dairyman  and  so  they  have  considerable 
influence  which  on  the  whole  has  been  used  in  a  way  to  materially  advance 
the  dairy  industry.  Many  companies  issue  helpful  reading  matter  to 
their  patrons,  and  occasionally  one  of  them,  for  the  instruction  of  its 
dairymen,  organizes  an  enormously  expensive  campaign,  such  as  that  of 
the  Supplees  against  tuberculosis. 

Basis  on  which  Milk  is  Purchased.— The  basis  on  which  dealers  and 
producers  do  business  naturally  varies;  there  may  or  may  not  be  a  con- 
tract between  the  two.  Where  the  dealer  holds  the  whip  hand  he  merely 


232  CITY  MILK  SUPPLY 

agrees  to  take  the  milk  the  dairyman  brings  him,  paying  therefor  what 
and  when  he  chooses,  or  a  few  weeks  in  advance,  he  may  set  the  price  of 
milk  for  the  ensuing  month.  In  better-developed  dairy  districts  sounder 
business  relations  exist;  written  contracts  are  made  for  6-  or  12-month 
periods.  These  contracts  vary  a  great  deal;  they  commonly  state  the 
price  to  be  paid  each  month  for  milk  and  often  contain  a  clause  to  the 
effect  that  the  daily  deliveries  of  milk  by  the  dairyman  shall  not  vary 
more  than  a  stated  percentage  above  or  below  the  amount  called  for  in 
the  contract.  Other  clauses  are  often  inserted  whereby  the  dairyman 
agrees  to  do  certain  things  such  as  to  exclude  certain  breeds  of  cows  from 
his  herd,  to  have  his  herd  tuberculin-tested  every  6  months,  not  to  use 
divers  kinds  of  feed,  to  build  a  milk  house  or  silos,  or  to  cool  his  milk 
right  after  milking  and  to  deliver  it  at  the  receiving  station  between 
certain  hours  and  below  a  fixed  temperature.  In  these  long-term  con- 
tracts the  price  paid  for  milk  varies  from  month  to  month,  usually  being 
lower  in  June  and  the  early  summer  months  than  in  mid- winter. 

The  basis  on  which  milk  is  bought  varies;  the  U.  S.  Department  of 
Agriculture  states  that  the  following  systems  of  purchase  are  in  common 
use: 

1.  By  the  quart  or  gallon. 

2.  By  the  can,  the  size  of  which  varies  from  8>^  to  40  qt.  or  more. 

3.  By  the  can,  with  the  stipulation  that  the  can  of  milk  must  come  up  to  the 
standard  weight. 

4.  By  the  can  or  gallon,  with  a  minimum  standard  for  butterfat  and  a  definite 
premium  per  gallon  for  each  0. 1  per  cent,  butterfat  above  a  certain  fat  test  as,  for 
instance,  3.8  per  cent. 

5.  By  the  gallon,  the  number  of  gallons  being  determined  by  dividing  the  weight 
of  the  milk  by  8.6. 

6.  By  weight  by  assuming  a  fixed  weight  for  a  can  of  milk  and  multiplying  it  by 
the  number  of  cans. 

7.  By  weight,  the  milk  being  actually  weighed. 

8.  By  weight,  as  by  No.  4,  with  in  addition  a  stated  minimum  standard  for  dairy 
farm  score  with  a  premium  for  points  scored  above  the  standard. 

9.  At  a  certain  rate  per  pound  for  butterfat  plus  so  much  per  100  Ib.  for  skim-milk; 
e.g.,  at  38  cts.  a  pound  for  butterfat  and  70  cts.  per  100  Ib.  for  skim-milk,  100  Ib.  of  milk 
would  bring  3.3  X  0.38  =  1.25  +  (96.7  X  70  =  68)  =  $1.93. 

10.  On  the  same  basis  as  No.  9,  except  that  the  weight  of  whole  milk  instead  of 
skim  is  considered. 

11.  By  weight,  with  additions  or  deductions  to  the  rate  according  as  the  percentage 
of  butterfat  rises  or  falls  above  or  below  an  established  standard.     Premiums  may  be 
paid  for  each  0.1  per  cent,  of  butterfat  above  the  standard,  and  deductions  made  from 
each  0.1  per  cent,  below  it  or  sometimes  premium  is  paid  only  for  milk  0.3  per  cent, 
above  the  standard  while  deductions  are  made  for  each  0.1  per  cent,  below  it. 

12.  Milk  is  bought  on  a  base  rate  which  is  established  for  each  month  in  the  year 
by  averaging  the  butterfat  content  of  the  milk  for  each  month  over  a  series  of  years 
and  fixing  the  rate  in  accordance  therewith,  a  premium  of  3  cts.  per  100  Ib.  in  summer 
and  4  cts.  per  100  Ib.  in  winter  being  paid  for  each  0.1  per  cent,  of  butterfat  that  the 
milk  runs  in  excess  of  the  average  and  a  like  deduction  being  made  for  each  0.1  per 


THE  MILK  CONTRACTOR  233 

cent,  that  the  milk  falls  below  it.  A  deduction  is  also  made  if  the  solids-not-fat  are 
less  than  8.5  per  cent.  Milk  of  less  than  2.5  per  cent,  butterfat  content  is  paid  for  on 
a  sweet-cream-fat  basis. 

13.  A  certain  price  is  paid  per  per  cent,  of  butterfat  per  gallon. 

14.  Milk  is  graded  and  paid  for  at  3  to  4  cts.  per  0.1  per  cent,  of  butterfat  per  100 
Ib.  for  grade  B  milk.    Grades  are  determined  by:  (1)  bacterial  content  of  the  milk;  (2) 
sediment  test;  (3)  acidity;  (4)  flavor  and  odor;  and  (5)  temperature  on  arrival  in  the 
city.     For  grade  A  milk,  a  premium  of  5  cts.  per  100  Ib.  is  added;  for  grade  C  milk,  a 
reduction  of  5  cts.  per  100  Ib.  is  made  from  grade  B  prices.     Should  a  producer 
furnish  grade  C  milk  for  2  successive  months  the  dealer  may  cancel  the  contract. 

15.  Extra  prices  are  paid  farmers  for  special  milks  such  as  that  which  is  tuberculin- 
tested. 

Methods  of  purchase  which  do  not  take  into  account  the  percentage 
of  butterfat  in  the  milk  encourage  farmers  to  keep  high-producing  cows 
that  give  milk  of  low  butterfat  content.  In  general,  it  is  poor  policy  not 
to  pay  on  the  quality  basis.  Clean  milk  and  rich  milk  costs  more  to 
produce  than  thin  milk  or  dirty  milk;  therefore,  a  method  of  payment 
should  be  adopted  that  will  adequately  reward  the  producer  of  superior 
milk.  No  single  system  can  be  recommended  for  universal  use,  because 
the  character  of  the  trade  varies  and  should  decide  the  method  of  purchas- 
ing. Premium  for  barn  scores,  for  bacterial  counts,  etc.,  and  the  grading 
of  milk  are  most  likely  to  prevail  in  dairy  districts  supplying  a  well-regu- 
lated city  milk  trade.  Probably,  it  would  be  good  for  the  dairy  business 
if  all  milk  were  purchased  by  the  100  Ib.,  for  the  dealers  would  then  weigh 
the  milk  they  buy,  and  so  would  pay  only  for  that  they  actually 
receive;  which  would  cut  down  their  losses  from  short  measure  resulting 
from  battered  cans,  etc. 

The  dairy  division  of  the  Bureau  of  Animal  Industry  found  that  of 
87  plants  in  four  Eastern  cities,  six  bought  all  the  milk  by  weight,  21 
part  by  weight  and  part  by  measure  and  60  entirely  by  measure.  How- 
ever, as  it  was  the  larger  dealers  who  in  most  cases  bought  by  weight 
the  amount  of  milk  bought  on  this  basis  was  greater  than  the  figures 
indicate.  Tests  at  one  of  the  plants  that  was  buying  by  measure  of 
55  10-gal.  cans  showed  that  the  net  weight  of  milk  varied  from  80  to 
86^4  Ib.;  the  average  being  83J4  Ib.  or  2^  Ib.  less  than  the  accepted 
weight  of  10  gal.  of  milk.  The  average  net  weight  of  milk  in  this  dealer's 
quart  bottles  was  2.115  Ib.  which  means  that  he  was  getting  but  39.36  qt. 
of  milk  on  an  average  from  his  40-qt.  cans  or  he  was  running  a  loss  of 
1.6  per  cent,  per  can.  Loss  also  occurs  from  the  fact  that  much  of  the 
milk  that  is  bought  by  measure  is  afterward  cooled  and  contracts  in 
volume  in  the  process.  Experiments  show  that  in  cooling  milk  from  70° 
to  50°F.  the  shrinkage  is  at  least  0.2  per  cent.  Moreover  if  milk  were 
sold  by  the  pound  dairymen  would  think  in  terms  of  weight  instead  of 
bulk,  which  would  tend  to  encourage  them  to  weigh  the  milk  each  cow 
produced.  Or  stated  briefly,  the  use  of  the  pound  as  the  unit  of 
bargaining  tends  toward  exactness  and  elimination  of  waste. 


234  CITY  MILK  SUPPLY 

Sweet  cream  is  bought  on  the  butterfat  or  butterfat  and  skim-milk 
basis. 

Tendency  to  Concentration.  — Milk  producers  and  milk  consumers 
shrewdly  discuss  whether  the  milk  contractors  are  so  organized  locally 
and  nationally  as  to  constitute  a  monopoly.  It  is  claimed  that  a  few 
big  dealers  have  so  manipulated  things  that  they  can  dictate  to  the 
farmer  the  price  at  which  he  shall  sell  milk,  and  to  the  consumer  what  he 
shall  pay  for  it.  It  is  intimated  that  the  contractor's  profits  are  inordi- 
nate and  that  his  high  prices  to  consumers  have  curtailed  the  consump- 
tion of  milk  and  his  low  prices  to  the  farmers  have  caused  them  to  produce 
less  and,  therefore,  more  expensively. 

Some  producers  hold  that  the  schedules  of  prices  put  out  from  time 
to  time  by  the  big  dealers  are  so  similar  that  they  indicate  collusion  in 
fixing  the  price  of  milk,  and  that  unfair  methods  of  competition  are 
resorted  to  such  as,  at  loss,  underselling  the  small  dealer  in  the  city  and 
outbidding  him  in  the  country  till  his  business  is  ruined  and  he  is  com- 
pelled to  quit.  This  belief  that  coercive  policies  are  used  has  in  a  man- 
ner been  strengthened  by  the  Boston  Chamber  of  Commerce's  arraign- 
ment of  the  leased  car  system  and  its  subsequent  discontinuance  by  the 
Interstate  Commerce  Commission.  Certain  leaders  of  the  producers 
believe  that  the  only  way  the  dairy  farmer  can  secure  fair  prices  is  to  cease 
dealing  as  individuals  with  the  contractors  and  sell  his  milk  through  various 
sorts  of  farmer's  unions.  The  growth  of  this  feeling  has  led  milk  producers 
to  precipitate  great  milk  strikes  in  Chicago,  St.  Louis,  Boston  and  New 
York  that  have  attracted  national  attention  both  among  dairy  farmers 
and  consumers.  It  has  led  J.  J.  Dillon,  State  Commissioner  of  Foods 
and  Markets  of  New  York  State,  to  propose  that  a  plan  in  use  in 
Denmark  be  followed.  He  advises  that  in  every  dairy  section  of 
the  State  the  producers  should  form  a  local  association  and  legally 
appoint  it  the  agent  for  the  sale  of  their  milk,  thereby  putting  all  the  milk 
of  a  district  into  a  single  agency  for  sale  and  making  it  impossible  for 
the  members  to  sell  their  milk  personally.  The  local  organizations  would 
be  federated  in  a  single  agency  for  the  sale  and  distribution  of  milk. 
Acting  on  this  idea  the  Dairyman's  League  of  New  York  State  has  noti- 
fied its  members  that  it  is  in  a  position  to  market  their  milk  under  existing 
contracts  with  producers  and  has  designated  the  New  York  State  Depart- 
ment of  Foods  and  Markets  as  the  exclusive  agent  for  the  sale  of  milk. 
Thus  the  members  of  the  association  delegate  their  authority  to  sell  their 
milk  to  the  association  of  which  they  are  members  and  the  association 
concentrates  this  authority  in  the  State  Department.  This  action  is 
believed  by  Dillon  to  be  an  excellent  move  because  the  Department  has 
the  power  of  the  State  to  enforce  its  rulings  and  to  protect  the  dealers 
who  buy  the  milk  for  distribution.  This  plan  is  most  radical  and  whether 
it  will  succeed  or  not  will  be  observed  with  interest.  That  it  should  be 


THE  MILK  CONTRACTOR  235 

thought  of  indicates  deep  dissatisfaction  with  the  methods  that  have 
been  in  vogue. 

Among  milk  consumers  the  suspicion  is  rife  that  some  one  is  getting 
undue  profits  out  of  the  milk  business  but  whether  their  mistrust  is 
warranted  or  not  they  are  unable  to  tell  for  they  know  nothing  about  the 
cost  of  milk  production,  or  of  transporting  milk  and  the  contractors  have 
given  little  information  as  to  the  cost  of  conducting  their  part  of  the 
business. 

It  is  the  contractor's  contention  that  the  price  of  milk  is  fixed  only  by 
supply  and  demand,  that  the  similarity  of  schedule  is  to  be  expected 
because  the  producers  are  all  thoroughly  familiar  with  the  market  and 
the  scale  of  prices  is  merely  a  reflection  of  their  opinion  of  it.  Contractors 
admit  that  the  trade  of  small  dealers  is  from  time  to  time  absorbed,  but 
they  contend  that  this  is  because  the  milk  business  naturally  lends  itself 
to  monopoly,  because  the  expenses  of  conducting  a  small  business  are 
great  as  compared  with  that  of  conducting  a  large  one,  and  they  assert 
that  they  are  receiving  a  very  moderate  return  for  the  capital  they  have 
invested. 

Methods  of  Paying  Producers. — The  dealer's  check  is  sent  the  dairy- 
man weekly,  monthly  for  the  previous  month,  or  payment  for  a  month's 
milk  is  withheld  for  longer  periods;  in  some  cases  dealers  are  habitually 
2  or  3  months  in  arrears  to  the  dairyman.  In  many  instances  these  de- 
linquent dealers  fail,  which  has  led  some  States  to  enact  laws  compelling 
contractors  to  file  bonds  to  secure  their  purchases  of  milk  and  cream. 

Milk  Plants. — Milk  companies  build  stations  or  plants  for  handling 
milk  and  preparing  it  for  delivery.  These  plants  are  developments  of 
the  milk  room  or  milk  house  that  are  part  of  the  equipment  of  dairymen 
who  retail  their  own  milk.  Originally  such  houses  were  merely  conven- 
ient places  to  work  and  for  storing  milk  in  tanks  filled  with  well  or  spring 
water.  Sometimes,  if  dairymen  made  butter,  the  houses  were  equipped 
with  churns.  Later,  milk  coolers,  bottlers  and  separators  appeared  and 
the  dairymen  had  to  meet  the  problems  of  drainage,  disposal  of  wastes, 
etc.;  in  fact  these  milk  houses  became  stations  in  miniature. 

Milk  stations  may  be  divided  into  two  classes  according  to  whether 
they  are  located  in  the  country  or  the  city.  The  processes  through 
which  milk  is  put  in  the  two  classes  of  plants  are  much  alike,  the  principal 
difference  being  in  the  scale  on  which  they  are  conducted.  So  the 
detailed  discussion  of  them  that  follows  in  the  account  of  city  plants  is 
intended  to  cover  both. 

Country  Milk  Plants. — Country  plants  in  different  parts  of  the  United 
States  are  given  divers  names  being  variously  called  creameries,  milk- 
receiving  depots,  bottling  plants  and  shipping  stations.  They  are  usually 
owned  and  operated  by  city  milk  contractors,  but  in  some  instances  by 
farmers.  In  response  to  the  latest  development  in  the  city  milk  trade 


236 


CITY  MILK  SUPPLY 


country  milk  plants  have  multiplied ;  some  have  been  created  by  remodel- 
ing old  creameries  while  others  are  new,  being  designed  and  built  for  the 
special  purpose  for  which  they  are  used.  There  are  several  advantages 
in  the  country  milk  plant  system.  As  a  rule  it  is  not  necessary  to  invest 
so  much  money  in  country  as  in  city  plants;  usually  from  $2,000  to  $20,000 
according  to  the  character  of  the  building  and  its  equipment  is  enough. 
However,  if  a  contractor  buys  his  milk  in  several  widely  separated  dis- 


FIG.  39. — Country  milk  plant  at  Harvard,  Illinois. 

tricts  it  often  is  more  economical  to  concentrate  his  business  in  a  single 
city  plant  than  to  maintain  several  country  plants.  Labor  difficulties 
are  less  likely  to  occur,  for  the  men  in  the  country  can  live  more  comfort- 
ably on  their  wages  than  men  in  the  city  can  on  theirs  and  it  is  more 
difficult  to  foment  strife  among  employees  scattered  in  small  numbers 
in  several  plants  than  it  is  to  do  so  in  a  large  plant  with  many  on  the  pay- 
roll. Dairymen  dealing  directly  with  the  plant  managers  get  on  more 
harmoniously  than  they  do  with  officials  living  in  the  city  whom  they 
seldom  see.  The  country  milk  plant  effects  a  desirable  concentration  of 
country  business  for  either  by  a  system  of  auto  truck  collection  or  of 
having  dairymen  haul  directly  to  the  plant,  the  unsatisfactory  practice 
of  leaving  a  few  cans  of  milk  exposed  on  the  platform  of  little  way  sta- 
tions to  be  picked  up  by  milk  trains  is  abolished.  Country  plants  facili- 
tate the  grading  of  milk  which  is  becoming  a  powerful  factor  in  improving 
dairying. 

The  Item  of  the  Surplus.— It  is  the  opinion  of  many  that  surplus 
milk  is  better  handled  in  the  country  than  in  the  city.  The  production 
of  milk  is  at  the  maximum  during  June  and  decreases  gradually  through 


THE  MILK  CONTRACTOR  237 

the  succeeding  months,  but  in  general  there  is  no  fluctuation  from  day  to 
day  in  the  yield  of  the  cows1  except  in  response  to  severe  weather  condi- 
tions such  as  extreme  cold  or  heat  or  a  parching  drought.  Cows  yield 
steadily,  though  in  declining  amounts  as  the  lactation  period  progresses. 
The  demand  for  milk,  on  the  contrary  vacillates;  in  hot  days  more  milk 
is  used  than  on  cold  ones  and  on  stormy  days  the  amount  sold  in  stores 
is  less  than  in  fair  weather.  Many  families  go  away  for  Saturday  and 


Courtesy  of  Robert  Burnett. 

FIG.  40. — Country  milk  plant  of  Deerfoot  Farms,  Southboro,  Mass. 

Sunday  and  in  vacation  time  10  to  60  per  cent,  of  the  trade  leaves  certain 
parts  of  the  city.  Consequently,  the  dealer,  since  his  contract  compels 
him  to  take  the  full  quantity  of  milk  named  in  the  agreement,  often 
finds  himself  with  milk  over  and  above  what  can  be  disposed  of,  some- 
times to  the  amount  of  2  days'  supply,  and  occasionally  also  he  faces  a 
shortage  of  milk  which  can  only  be  made  up  by  purchasing  a  temporary 
supply  at  high  price  in  a  territory  that  very  likely  is  far  away,  thus  impos- 
ing unusual  transportation  charges.  In  times  of  a  surplus  the  only  way 
to  prevent  serious  losses  is  to  manufacture  the  milk  into  butter,  cheese 
and  other  dairy  byproducts,  but  since  milk  of  the  grade  that  goes  into 
city  milk  supply  commands  a  price  higher  than  can  be  realized  from  the 
manufactured  products,  at  best,  the  loss  can  only  be  minimized.  Unfor- 
tunately the  surplus  is  most  likely  to  occur  when  bottom  prices  for  butter 
and  cheese  prevail  so  that  loss  is  almost  inevitable.  Peck  states  that  the 
Abbot's  Alderney  Dairies  of  Philadelphia  for  20  years  have  kept  books 
in  such  a  way  as  to  show  the  cost  of  this  factor  of  supply  and  demand 
that  this  company  finds  the  loss  to  approach  $0.005  per  quart  on  entire 
sales.  As  instances  of  sudden  shrinkage  of  the  milk  supply  he  cites  actual 


238  CITY  MILK  SUPPLY 

losses  experienced  by  the  Sheffield  Farms-Slawson,  Decker  Co.  of  New 
York  and  by  the  Bowman  .Dairy  Co.  of  Chicago  in  the  summer  of  1913. 
The  shrinkage  in  the  supply  of  the  former  company  on  July  10  to  July  11 
was  13,145  Ib.  and  from  July  13  to  July  14  was  18,460  lb.;  coincidently, 
the  increase  in  orders  from  July  11  to  July  12  was  10,170  lb.  The  total 
amount  of  milk  purchased  to  make  up  shortage  in  July  was  792,655  lb. 
and  in  August  3,558,865  lb.,  making  the  cost  over  the  regular  price  of 
milk  $15,367.96.  The  latter  company  experienced  a  milk  shrinkage  on 
July  30  to  July  31  of  15,406  lb.,  on  Aug.  8  to  Aug.  9  of  20,339  lb.,  and  on 
Sept.  19  to  Sept.  22,  of  29,850  lb.  The  total  shrinkage  in  this  milk  supply 
from  July  10  to  Sept.  22  was  211,834  lb. 

H.  P.  Hood  and  Sons  of  Boston  state  that  in  March,  1911,  it  was  pos- 
sible for  them  to  dispose  of  but  61.5  per  cent,  of  the  milk  bought,  leaving 
38.5  per  cent,  to  be  worked  up  into  butter  and  casein  but  that  in  Novem- 
ber purchases  and  sales  balanced.  This  firm  estimates  that  in  a  series  of 
years  20  per  cent,  of  the  milk  purchased  will  have  to  be  made  up  into 
butter  and  casein. 

It  should  be  readily  appreciated  that  this  item  of  the  surplus  presents 
a  most  serious  difficulty.  In  the  last  analysis  the  cost  of  caring  for  it 
falls  on  the  milk  consumer  but  its  first  effects  come  more  directly  on  the 
dealer  who  has  to  finance  the  loss  for  the  time  being.  There  is  temptation 
for  a  dealer  who  finds  himself  oversupplied  with  milk  to  resort  to  rate 
cutting  which,  if  yielded  to,  upsets  business  and  in  the  long  run  has  a  bad 
effect  that  is  felt  by  all.  The  burden  of  carrying  this  surplus  is  best 
adjusted  by  working  up  the  extra  milk  so  as  to  obtain  for  it  the  best 
possible  price.  By  doing  the  manufacturing  in  the  country  the  cost  of 
transportation  of  the  milk  at  least  is  saved. 

The  North  System. — However,  the  chief  reason  for  maintenance  of 
country  milk  plants  is  found  in  the  vital  principle  of  the  North  system, 
namely,  that  a  single  central  plant  is  needed  in  the  dairy  district  to  cool, 
pasteurize,  standardize  and  store  the  milk  and  to  clean  and  sterilize  the 
tinware  used  by  the  farmers,  it  being  unreasonable  to  expect  them  to  do 
this  work  because  they  have  not  the  training  for  it  and  because  of  the 
unnecessary  expense  that  would  be  incurred  should  each  farmer  invest  in 
the  requisite  apparatus  and  expend  time  and  labor  in  preparing  his  milk 
for  market  that  can  be  greatly  economized  by  handling  the  milk  of  all 
the  farmers  together.  In  fine,  better  milk  is  obtained  through  the  coun- 
try milk  plant  system  than  under  that  of  city  plants.  In  some  cities 
like  Chicago  with  the  dairy  districts  at  their  very  gates  the  city  plants 
have  largely  disappeared,  practically  all  of  the  milk  being  shipped  in 
bottles  from  the  country  to  the  city. 

Handling  of  Milk  in  Country  Plants. — The  operations  milk  goes 
through  in  country  plants  varies  a  great  deal  according  to  whether  the  milk 
receives  merely  preliminary  treatment  for  shipment  to  city  plants  where 


THE  MILK  CONTRACTOR  239 

it  receives  final  preparation  for  the  market  or  whether  the  milk  is  made 
ready  for  city  delivery.  Country  plants  may  be  simply  receiving  stations 
where  the  milk  is  weighed,  cooled,  recanned  and  loaded  into  cars  or  they 
may  be  very  completely  equipped  stations  where  the  milk  -is  weighed  and 
clarified,  after  which  part  is  separated  to  get  the  cream  requisite  for  city 
consumption  and  for  use  in  standardizing  the  rest.  After  standardiza- 
tion, the  milk  is  canned  without  pasteurization  or  after  having  gone 
through  this  process  is  canned  or  bottled  and  then  cooled  to  between 
40°  to  50°F.,  finally  being  loaded  onto  the  cars.  The  skim-milk  is  utilized 
in  various  ways;  it  may  be  sold  back  to  the  farmers  for  feeding  to  stock 
in  which  case  it  should  always  be  pasteurized  to  prevent  the  dissemina- 
tion of  tuberculosis  and  other  diseases  among  the  animals  or  the  casein 
may  be  precipitated  with  dilute  acids  and  sold  to  concerns  that  manu- 
facture it  into  size  and  other  products.  In  some  country  milk  plants  by 
the  use  of  bacterial  cultures  milk  beverages  such  as  buttermilk,  koumyss 
and  others  are  made  from  the  skim-milk. 

Cream. — Cream  is  sent  to  the  city  market  with  varying  butterfat 
content  under  trade  names  such  as  No.  9,  No.  17,  single,  double,  coffee, 
light  creams,  etc.,  that  have  no  exact  meaning  but  that  convey  to  the 
customer  the  idea  that  the  creams  are  of  different  richness.  Thus  one 
dealer's  light  cream  may  contain  12  per  cent,  butterfat,  another's  15 
per  cent,  and  still  another  17  per  cent.,  their  double  creams  will  be  much 
richer  but  improbably  twice  as  rich  and  they  will  differ  in  like  manner 
from  one  another  in  butterfat  content.  The  separator  makes  it  easy 
to  control  the  percentage  of  butterfat  in  cream  for  it  is  so  constructed 
that  by  adjusting  the  cream  screw  the  milk  may  be  closely  or  lightly 
skimmed.  Also  from  a  heavy  cream,  one  of  any  desired  lower  butterfat 
content  can  be  made  up  by  adding  either  whole  or  skim-milk  in  proper 
proportion.  Of  late  years  there  has  been  marked  increase  in  the  demand 
for  cream,  not  only  for  manufacture  into  ice  cream  and  other  dairy 
products,  but  for  preparing  fancy  dishes  in  hotels  and  for  family  use  so 
that  the  sale  of  sweet  cream  has  become  an  important  part  of  the  city 
milk  business.  In  some  markets  the  price  of  cream  actually  determines 
the  price  of  milk.  Sometimes  country  milk  plants  are  wholly  devoted 
to  the  preparation  and  shipping  of  sweet  cream.  In  such  plants  the 
milk  is  separated,  the  cream  pasteurized,  cooled,  canned  and  loaded  into 
cars  while  the  skim-milk  is  worked  up  separately. 

The  Cream  Separator. — The  separator  is  to  be  found  on  many  dairy 
farms  and  in  most  milk  plants,  in  fact  it  is  all  but  indispensable  to  every- 
one who  sells  milk  and  cream.  By  the  separator,  milk  can  be  more 
rapidly  and  efficiently  skimmed  than  by  gravity;  the  richness  of  the 
cream  can  be  controlled  and  the  separation  can  be  done  at  any  time  so 
that  waiting  for  the  cream  to  rise  is  unnecessary.  The  separator  works 
on  the  centrifugal  principle.  The  whole  milk  enters  a  revolving  bowl 


240  CITY  MILK  SUPPLY 

and  the  heavy  particles  are  thrown  to  the  outside  wall  making  the  skim- 
milk,  while  the  lighter  particles,  the  butterfat,  remain  in  the  center 
forming  the  cream.  Bowls  are  run  at  a  high  rate  of  speed,  those  of 
small  diameter  turning  fastest;  some  make  16,000  r.p.m.  Within  the 
bowl  are  discs  or  leaves  over  which  the  milk  spreads  in  thin  films  as  it 
enters  so  that  it  is  quickly  given  a  centrifugal  motion  and  the  separation 
of  the  cream  accelerated  accordingly.  In  some  types  of  separators  a 
revolving  flange  gives  a  rotary  impulse  to  the  incoming  milk  with 
the  same  result.  The  length  of  time  the  milk  remains  in  the  bowl  is 
determined  by  the  obstructions  therein.  There  are  a  number  of  things 
that  effect  the  efficiency  of  the  skimming  process,  viz. : 

1.  The  speed  of  the  bowl. 

2.  The  steadiness  of  the  bowl. 

3.  The  temperature  of  the  milk. 

4.  Rate  of  skimming. 

5.  Richness  of  the  cream. 

6.  Acidity  of  the  cream. 

7.  Character  of  the  milk,  due  to  breed  of  cow,  stage  of  lactation  and  the  richness 
of  the  milk. 

The  richness  of  the  cream  is  controlled  by  the  cream  screw  in  the 
separator  bowl ;  turning  the  screw  toward  the  center  of  the  bowl  throttles 
the  outlet  and  increases  the  richness  of  the  cream,  and  turning  it  away 
from  the  center  opens  the  outlet  and  makes  the  cream  thinner. 

With  the  increase  of  speed  more  skim-milk  is  forced  out  the  openings, 
making  the  cream  richer;  the  effect  of  the  speed  is  more  marked  when  the 
cream  screw  is  set  to  deliver  a  high  percentage  of  fat.  The  rate  of  inflow 
of  the  milk  is  affected  by  the  speed  of  the  bowl  because  the  higher  the 
speed  the  greater  the  tendency  to  produce  a  partial  vacuum  in  the  revolv- 
ing bowl.  As  a  rule  when  the  separator  is  run  at  three-fourths  its  normal 
speed  the  loss  in  skim-milk  is  two  to  three  times  as  great  as  when  it  is 
run  at  the  indicated  rate.  Machines  usually  leave  the  factory  adjusted 
so  that  10  per  cent,  of  the  milk  put  in  comes  out  as  cream. 

The  separator  should  run  smoothly  for  all  vibration  or  jarring  in- 
creases the  loss  in  fat.  For  this  reason  the  separator  should  set  level  and 
be  mounted  on  a  rigid  foundation.  An  unbalanced  bowl  or  loose  or 
dirty  bearings  cause  the  separator  to  run  unevenly. 

The  temperature  of  the  milk  at  skimming  is  important;  it  should  be 
between  90°  and  100°F.  The  effect  of  reducing  the  temperature  of  the 
milk  below  this  is  to  increase  the  percentage  of  butterfat  in  the  skim- 
milk.  Between  70°  and  80°F.  there  is  an  appreciable  loss  of  butterfat 
and  at  lower  temperatures  it  is  serious.  The  loss  is  caused  by  the  greater 
viscosity  of  the  cream  at  low  temperatures  which  makes  it  pass  slowly 
through  the  outlet  of  the  bowl.  The  milk  can  be  so  cold  that  the 
separator  will  not  deliver  the  cream. 


THE  MILK  CONTRACTOR  241 

A  change  in  the  rate  of  inflow  of  the  milk  changes  the  ratio  of  skim- 
milk  to  cream  for  while  a  diminution  in  the  inflow  reduces  both  the  milk 
and  cream,  the  latter  is  most  affected  so  that  decreasing  the  inflow  reduces 
the  percentage  of  fat  in  cream. 

High  acidity  of  the  milk  reduces  the  cream. 

The  percentage  of  fat  in  the  cream  varies  directly  with  the  percentage 
of  fat  in  the  whole  milk.  The  size  of  the  fat  globules  varies  with  the 
breed  of  the  cow  and  the  larger  the  globules  the  more  readily  the  milk 
skims.  It  is  because  of  the  large  proportion  of  small  globules  in  milk  at 
the  end  of  the  lactation  period  that  strippers'  milk  does  not  skim  well. 

The  separator  should  be  properly  cared  for  in  order  that  the  milk 
which  is  run  through  it  may  be  uninjured  and  that  the  separator  may 
last  long. 

A  great  deal  of  harm  has  been  done  butter  manufacturers  and  city 
milk  dealers  by  unscrupulous  agents  of  separator  companies  represent- 
ing to  farmers  that  the  particular  machine  they  were  touting  was  so 
easy  to  clean  that  but  little  time  need  be  spent  in  washing  it;  in  many 
instances  it  has  been  stated  that  the  machine  might  be  sufficiently  cleaned 
by  merely  running  water  through  it  at  the  end  of  the  separating.  Such 
statements  are  grossly  untrue  and  if  the  advice  is  followed  must  inevitably 
result  in  the  production  of  inferior  milk  and  cream.  Milk  clings  to  the 
bowl  parts  of  the  separator  and  only  patient  and  thorough  cleaning  will 
remove  it.  If  the  least  bit  of  milk  is  left  adherent  it  will  serve  as  food 
for  bacterial  growths  that  will  contaminate  the  milk  as  it  is  run  through 
the  separator.  The  separator  should  be  flushed  with  cold  water  at  the 
end  of  the  run;  then  it  should  be  taken  apart  and  the  parts  washed,  first 
in  cold  water  then  in  hot  water  and  washing  powder  and  finally  they 
should  be  rinsed.  Then  they  should  be  hung  up  in  a  light  airy  place  to 
dry  until  needed  again.  If  the  parts  are -put  together  in  the  machine 
they  are  likely  to  rust.  Where  there  are  facilities  for  doing  so,  the  parts 
should  be  sterilized  before  use. 

Separators  must  be  kept  in  good  order  or  they  will  wear  out  more 
quickly  than  they  should.  The  gearings  should  be  flushed  once  a  month 
with  a  good  grade  of  kerosene  and  then  reoiled  with  lubricating  oil. 

In  purchasing  a  separator  attention  should  be  paid  to  the  following 
points : 

1.  Capacity;  the  machine  should  be  large  enough. 

2.  Cost;  a  cheap  machine  is  a  poor  investment. 

3.  Durability;  standard  machines  are  most  likely  to  give  good  service. 

4.  Ease  of  cleaning  is  highly  important;  the  more  simple  the  bowl  device  the  better. 

5.  Spindle;  whether  attached  or  detached.    Most  standard  machines  have  detached 
spindles  which  prevents  them  getting  out  of  line. 

6.  Oiling  system;  an  important  feature  for  the  machine  should  be  kept  well-oiled 
with  the  gears  bathed  in  oil. 

7.  Speed  of  the  machine. 

8.  Efficiency. 
16 


242  CITY  MILK  SUPPLY 

Advantages  of  City  Milk  Plants. — The  system  of  building  milk  plants 
in  the  city  is  older  than  that  of  locating  them  in  the  country;  it  had  its 
origin  in  the  simple  fact  that  the  first  city  dealers  had  to  have  a  place  to 
care  for  the  milk  they  received  from  the  country  and  headquarters  for 
the  transaction  of  business.  As  business  grew,  so  did  the  plants,  for  more 
space  was  required  for  handling  the  milk  and  for  years  there  was  no  at- 
tempt of  the  contractor  to  extend  his  operations  into  the  country.  In 
time,  however,  country  plants  were  developed,  largely  because  certain 
firms  that  were  making  condensed  milk  and  that  were  also  in  the  city 
milk  business  found  a  portion  of  the  latter  could  be  profitably  carried  on 
from  the  dairy  centers  they  had  built  up  around  their  condenseries. 
This  led  to  a  comparison  of  the  merits  of  country  and  of  city  milk  plants. 
In  favor  of  the  latter  it  was  found  that  the  business  of  several  dairy 
districts  can  be  concentrated  in  a  single  plant  and  that  they  possessed 
certain  other  advantages.  Milk  cars  will  not  hold  as  many  gallons  of 
bottled  milk  as  of  milk  in  cans  and  the  glass  bottles  and  cases  weigh  more 
than  the  cans  required  for  an  equal  quantity  of  milk,  consequently  it 
costs  more  per  pound  to  transport  bottled  milk  than  bulk  milk.  The 
outlay  for  bottles  and  cases  is  necessarily  greater  when  milk  is  shipped  in 
bottles  than  when  in  cans  for  there  must  be  in  addition  to  the  bottles 
and  cases  required  for  daily  delivery  in  the  city  enough  more  in  transit 
to  assure  an  adequate  supply  in  both  city  and  country.  As  there  is 
more  glassware  in  daily  circulation  the  breakage  bill  is  higher  in  the  sys- 
tem of  country  plants.  Broadly  speaking  small  country  plants  are  not 
run  on  such  a  high  plane  of  efficiency  or  at  such  low  cost  as  large  city 
ones.  There  is  a  saving  of  time  in  the  city  from  having  the  milk  arrive 
from  the  country  bottled  and  ready  for  distribution  but  this  is  offset  by 
the  delay  at  the  country  end  that  may  arise  from  irregular  delivery  of 
milk  at  the  plant  by  the  farmers  and  certainly  does  so  from  the  fact 
that  small  pasteurizing  units  cannot  handle  the  output  as  rapidly  as 
large  ones.  Moreover,  interruption  of  service  either  through  breaking 
down  of  the  machinery  or  other  causes  may  be  serious  enough  to  make  the 
milk  miss  the  train  entirely  which  is  not  likely  to  occur  when  the  milk  is 
shipped  in  cans  to  city  plants.  Thus  the  milk  available  for  city  delivery 
may  be  curtailed,  and  inconvenience  the  customer,  with  consequent  loss 
of  trade  to  the  contractor,  whereas  if  the  milk  train  is  late  the  worst 
that  is  likely  to  happen  is  the  loss  of  a  few  hours  time  in  the  plants. 
However,  by  good  management  many  country  milk  plants  are  regularly 
supplying  milk  to  the  city  without  interruptions  occurring.  City  plants, 
too,  have  perhaps  been  unconsciously  favored  by  boards  of  health  be- 
cause at  less  cost  a  more  constant  and  so  a  more  thorough  supervision 
can  be  maintained  over  them  than  over  country  plants. 

General  Features  of  City  Milk  Plants. — City  milk  plants  are  usually 
located  near  railroad  terminals  but  there  is  developing  a  tendency  to 


THE  MILK  CONTRACTOR  243 

place  them  in  the  center  of  the  territory  of  distribution.  They  are  often 
rambling  structures  that  in  many  cases  housed  the  contractors  business 
when  it  was  small  and  required  little  machinery  and  have  been  enlarged 
as  the  growth  of  the  business  required,  by  the  purchase  and  addition  of 
adjoining  structures  and  by  the  building  of  annexes.  So  these  plants 
are  only  indifferently  adapted  to  the  business.  In  fact,  one  of  the  things 
that  has  delayed  the  introduction  of  cost  accounting  into  the  city  milk 
business  has  been  these  very  plants  for  they  necessitate  the  shifting  of 
employees  from  job  to  job  in  a  way  that  baffled  all  attempts  at  good 
management  and  accurate  keeping  of  time.  Of  late  years  there  have  been 
erected  in  Milwaukee,  Indianapolis,  Philadelphia,  New  York  and  other 
cities  plants  that  are  especially  designed  for  the  city  milk  business.  No 
expense  has  been  spared.  Their  sites  are  carefully  chosen;  they  are 
marvels  of  sanitary  construction;  contain  the  latest  machinery  for  pre- 
paring milk  for  delivery  to  the  consumer  and  for  handling  it  in  the  most 
orderly,  rapid  and  economical  manner.  The  buildings  contain  huge 
vats  for  mixing  and  storing  the  milk,  machines  for  clarifying,  pasteurizing 
and  bottling  it,  apparatus  for  making  butter,  cheese,  milk  beverages 
and  homogenized  milk,  repair  shops,  laundries,  and  power  plants  for 
making  steam  and  driving  the  machinery.  There  are  also  chemical  and 
bacteriological  laboratories  besides  lunch  rooms  for  the  employees,  rooms 
for  the  drivers  to  use  when  making  up  their  accounts,  offices  for  the  offi- 
cials and  clerical  force,  garages,  wagon  sheds,  stables  and  smithies.  To 
one  who  has  never  visited  these  large  city  milk  plants  it  is  difficult  to 
comprehend  the  scale  on  which  the  business  is  done.  What  for  the  time 
being  will  be  the  largest  of  them  all  is  to  be  erected  in  New  York  City  in 
1916.  It  will  be  a  six-story  plant  having  a  frontage  of  252  ft.  and  a  depth 
of  from  100  to  125  ft.  The  cost  of  the  building  alone  will  be  $300,000; 
it  will  have  a  refrigerating  plant  of  a  daily  capacity  of  12,000  tons  and  will 
employ  125  to  150  men.  In  most  of  these  large  plants  are  stores  for  the 
sale  of  milk  and  dairy  products  as  well  as  of  eggs  which  are  often  handled 
as  a  side  line  by  city  milk  dealers.  Sometimes  cafeterias  where  dairy 
lunches  are  served  are  established.  The  milk  business  is  absorptive  in 
character  and  some  of  the  large  dairy  companies  become  real  or  virtual 
owners  of  restaurants,  ice-cream  factories,  confectionery  establishments, 
bakeries,  etc. 

These  huge  milk  plants  can  be  supported  only  by  the  great  metro- 
politan centers  but  their  advantages  are  so  great  that  even  in  the  smaller 
cities  similar  but  smaller  plants  have  been  built.  A  single  plant  may  be 
capable  of  handling  the  entire  business  of  such  places  but  sometimes 
competing  firms  each  put  up  a  plant  with  the  result  that  neither  thrives. 
More  commonly  the  first  company  to  build  secures  a  monopoly  of  the 
best  part  of  the  business  through  its  ability  to  pasteurize  the  milk,  give 
it  adequate  cold  storage  and  to  serve  the  public  promptly.  Many  boards 


244  CITY  MILK  SUPPLY 

of  health  would  like  to  pass  ordinances  requiring  that  all  or  a  part  of 
the  milk  should  be  pasteurized  but  are  deterred  from  doing  so  by  the 
fact  that  such  an  ordinance  might  put  some  men  of  a  moderate  amount  of 
capital  out  of  business  and  might  tend  to  drive  a  part  of  the  business  of 
others  to  the  large  plant  already  equipped  to  pasteurize.  Also  there-  are 
cities  which  have  no  rnilk  plant,  that  might  support  one  if  the  milk  of  all 
the  dealers  could  be  handled  in  a  single  plant.  Out  of  these  conditions 
has  grown  the  demand  on  the  part  of  the  public  that  the  dealers  shall 
get  together  and  erect  a  plant  where  all  the  milk  shall  be  pasteurized, 
cooled  and  stored  or  that  a  municipal  plant  shall  be  put  up  for  the  purpose. 
Competition  in  the  milk  trade  is  so  very  keen  that  it  no  doubt  will  be 
difficult  to  get  dairymen  to  assent  to  either  plan  but  there  is  strength 
in  the  movement  and  it  may  succeed. 

The  preparation  of  milk  for  the  market  varies  in  different  city  milk 
plants.  The  smallest  are  merely  depots  where  raw  milk  is  received, 
bottled  and  held  at  low  temperature  for  delivery.  In  the  largest,  milk  is 
tested  for  odors,  and  flavor,  and  sediment,  at  the  receiving  platforms  and 
then  dumped  into  mixing  vats  from  which  it  passes  through  the  clarifier 
into  standardizing  vats  where  it  is  brought  to  the  butterfat  test  which  the 
contractor  has  determined  the  milk  he  puts  out  to  his  trade  shall  have. 
If  the  milk  is  not  to  be  used  at  once  it  then  goes  to  insulated  cold  storage 
tanks  where  it  is  kept  at  low  temperature  until  it  is  needed.  Milk  from 
the  standardizing  vats  or  the  storage  tanks  is  pasteurized  after  which  it  is 
put  into  cans  for  the  wholesale,  or  into  bottles  for  the  retail  trade.  It  is 
then  cooled  at  once  to  between  35°  and  50°F.  and  kept  in  refrigerators  or 
cold  rooms  till  wanted  for  delivery.  Most  of  the  large  plants  are  equipped 
for  the  manufacture  of  milk  beverages  and  for  working  up  the  milk  that  is 
returned  on  the  delivery  wagons  and  all  other  surplus  milk,  as  butter  and 
cheese. 

Classification  of  City  Milk  Plants. — There  no  doubt  is  some  difference 
of  opinion  as  to  what  sort  of  an  establishment  may  properly  be  called  a 
city  milk  plant  for  some  would  restrict  the  term  to  plants  that  represent 
a  large  investment  of  capital  and  handle  large  volumes  of  milk  while  others 
would  apply  the  term  more  generally.  It  seems  that  the  name  may  be 
given  to  any  place  where  a  regular  business  of  preparing  milk  for  the 
retail  trade  is  carried  on.  Accepting  this  view  city  milk  plants  may  be 
placed  in  two  groups  as  follows: 

Group  1. — Single-story  plants:  plants  occupying  a  basement  only; 
plants  occupying  a  ground  floor  and  basement;  plants  occupying  the 
ground  floor  only. 

Group  2. — Plants  of  more  than  one  story. 

Basement  Plants. — Basement  plants  may  be  perfectly  sanitary  but 
few  are  so.  As  a  rule  they  are  operated  by  small  dealers  with  inadequate 
capital  and  are  located  in  the  dealer's  dwelling  or  in  the  buildings  whose 


THE  MILK  CONTRACTOR  245 

principal  use  is  for  some  other  purpose  than  the  milk  business.  Both  of 
these  conditions  are  bad;  in  the  one  case  the  appearance  of  infectious 
disease  in  the  household  will  cripple  the  business,  and  the  inevitable  con- 
stant communication  between  the  family  and  the  dairy  tends  to  make  the 
basement  dirty  and  smelly  with  the  result  that  the  milk  becomes  tainted 
with  unpleasant  odors;  in  the  other  the  most  incongruous  sorts  of  business 
are  carried  on  under  the  same  roof  with  the  milkman's.  Basement  rooms 
are  difficult  to  light,  ventilate  and  keep  free  from  odors.  Street  dust 
polluted  with  animal  excretions  gravitate  naturally  to  the  basement. 
Often  basement  rooms  are  not  ceiled  and  dust  sifts  down  through  cracks 
in  the  floor  above,  or  even,  if  there  is  a  ceiling,  it  is  likely  to  be  rough  and 
cracked  and  therefore  a  source  of  dirt  rather  than  an  aid  in  cleanliness. 
The  plumbing  in  the  building  may  be  defective  and  so  admit  odors.  Base- 
ment windows  are  not  easily  kept  clean  and  rubbish  often  accumulates 
against  them.  As  the  equipment  of  all  city  milk  plants  is  determined  by 
the  volume  of  trade,  these  basement  plants,  since  they  do  a  small  business, 
are  apt  to  be  underequipped  and  such  apparatus  as  they  do  have  is  likely 
to  be  rather  primitive  and  often  badly  worn.  So  in  general  it  is  the 
policy  of  boards  of  health  to  eliminate  depots  of  this  type. 

Ground-floor  and  Basement  Plants. — Plants  of  the  ground-floor  and 
basement  type  are  often  of  considerable  size.  In  some  instances  the  base- 
ments may  be  of  such  a  sort  as  to  invite  serious  criticism;  in  others  they 
are  all  right.  In  plants  of  this  kind  the  milk  is  sampled  at  the  receiving 
platform,  weighed  in  a  can  sunk  in  the  floor  from  which  it  is  run  into  a 
vat  in  the  basement.  Thence  it  is  pumped  to  pasteurizing  machines  on 
the  ground  floor.  The  pumps,  and  the  piping  connected  thereto  are 
difficult  to  clean  and  on  that  score  are  objectionable.  On  the  ground  floor 
the  milk  may  be  pumped  from  machine  to  machine  or  the  several  ma- 
chines may  be  located  on  platforms  one  above  another  so  that  milk  can 
flow  by  gravity  through  the  series.  For  example,  from  the  mixing  tanks  in 
the  basement  milk  may  be  pumped  to  the  pasteurizer  on  the  highest 
platform,  pass  through  it  and  flow  over  the  cooler  on  the  next  lower  plat- 
form and  thence  into  the  bottler  on  the  lowest  platform  of  all. 

Single -story  Plants. — In  plants  that  are  all  on  the  ground  floor  the 
milk  is  pumped  from  one  machine  to  another,  several  pumps  being  utilized 
for  the  purpose. 

Plants  of  More  Than  One  Story. — Plants  of  the  second  group,  that  is 
of  two  stories  or  more,  usually  belong  to  large  dairy  companies  and  repre- 
sent very  large  investments  of  capital.  Milk  is  received  on  the  ground 
floor  and  is  sometimes  dumped  into  tanks  and  raised  to  the  top  of  the 
building  by  pumps  but  as  they  are  somewhat  difficult  to  clean,  it  usually  is 
hoisted  in  the  delivery  cans  to  the  highest  story  and  dumped  there. 
Thence  it  is  carried  from  one  process  of  handling  to  another  downward 
by  gravity  from  story  to  story  till  it  reaches  the  ground  floor  again,  all 
cased  and  ready  for  delivery. 


246  CITY  MILK  SUPPLY 

Minimum  Requirements  for  a  City  Milk  Plant. — Sooner  or  later  in 
every  city  the  question  arises  as  to  what  the  law  shall  require  in  the  sim- 
plest and  least  expensive  milk  plants.  The  answer  which  the  practical 
experience  of  those  cities  that  have  studied  the  problem  seems  to  give  is 
that  these  plants  should  have  at  least  three  rooms,  namely;  a  boiler  room, 
a  washroom  and  a  milk-handling  room  with  refrigerators  or  other  provi- 
sion for  keeping  the  milk  cool.  The  arrangement  of  these  plants  should 
be  such  that  the  dirt  of  the  boiler  room  shall  be  confined  there  and  that 
the  bottling  room  shall  be  effectively  isolated  from  the  litter,  steam  and 
odors  of  the  washroom. 

Environment  of  the  Milk  Plant. — With  these  general  observations  on 
country  and  city  milk  plants  we  may  proceed  to  more  particular  considera- 
tion of  city  plants  and  the  handling  of  milk  therein.  In  the  first  place, 
it  should  be  noted  that  the  environment  of  a  milk  plant  is  important;  it 
should  be  put  where  it  will  be  as  free  as  possible  from  contaminating 
surroundings.  Badly  built  latrines,  hog  pens,  chicken  yards,  manure 
heaps  and  surface  drains  carrying  slops  and  excrementitious  matter  are 
all  to  be  avoided.  There  should  be  abundance  of  sunlight  because  work 
can  be  better  and  more  cheerily  done  in  a  well-lighted  plant  than  in  a  dark 
one,  because  sunlight  has  some  disinfecting  value  and  because  of  the  ad- 
vertising value  that  good  lighting  has.  One  of  the  large  plants  of  the 
central  west  is  widely  known  as  the  " sunlight  dairy"  and  a  large  con- 
tractor in  Philadelphia  makes  an  attractive  appeal  to  the  public  through 
a  picture  showing  the  situation  of  his  plant  next  to  a  fine  public  park. 
Pure  air  is  essential;  to  locate  a  plant  in  a  district  where  noisome  odors 
prevail  is  poor  policy  and  it  is  important  that  the  air  be  free  from  dust. 
Unpaved  streets  are  usually  very  dusty  and  so  are  to  be  avoided  in  choos- 
ing  the  site  for  a  milk  plant  as,  for  the  same  reasons,  are  the  much-traveled 
thoroughfares  of  the  city.  However,  the  plant  must  be  where  these  main 
avenues  of  distribution  and  the  lines  over  which  the  milk  comes  to  the 
city  are  easily  and  quickly  reached.  In  some  of  the  large  cities  the  air 
entering  the  plants  is  filtered  or  washed. 

General  Plan  of  the  Milk  Plant. — The  layout  of  a  plant  should  be  such 
that  the  milk  can  be  handled  with  ease,  certainty,  and  economy.  A  poorly 
designed  plant  results  in  unnecessary  labor  and  expense  because  it 
compels  extra  handling  of  the  milk  and  long  time-consuming  trips  from 
one  part  of  the  building  to  another.  In  small  plants  there  should  be  a 
separate  washroom,  boiler  room,  milk-handling  room  and  refrigerating 
room.  Large  plants  should  have  a  boiler  room  or  power  plant,  a  receiving 
room,  washroom,  milk-handling  room,  refrigerating  room  and  sales  room. 
The  rooms  for  receiving  and  for  handling  the  milk  should  have  a  minimum 
of  piping.  The  absence  of  toilet  conveniences  for  the  employees  should 
be  regarded  as  a  serious  defect  but  water  closets  should  not  communicate 
with  any  room  in  which  milk  is  handled;  latrines  should  be  100  ft.  from 


THE  MILK  CONTRACTOR  247 

the  building  and  should  have  flyproof  and  ratproof  vaults.  No  room 
used  for  domestic  purposes  should  be  directly  connected  to  the  milk 
plant.  The  horse  stable  should  be  entirely  separate  from  the  plant. 

Water  Supply  of  the  Milk  Plant.— The  water  supply  should  be  abun- 
dant, clean  and  safe.  When  the  public  water  supply  is  used  the  bacteri- 
ological and  sanitary  chemical  analyses  of  the  city  or  State  are  usually 
available  and  can  be  depended  upon.  It  will  usually  be  found  econom- 
ical to  have  in  addition  a  mineral  analysis  of  the  water  with  the  analyst's 
statement  of  how  the  water  should  be  corrected  for  boiler  use.  This  is 
particularly  necessary  in  regions  of  hard  or  corrosive  waters.  The  con- 
tractor who  depends  on  the  advice  of  salesmen  of  boiler  compounds  in  the 
purchase  of  correctives  is  likely  to  be  badly  deceived.  Where  the  con- 
tractor develops  a  private  water  supply  for  his  plant  he  should  have 
periodical  bacteriological  and  chemical  analyses  made  of  the  water  and 
should  keep  them  carefully  on  file  that  he  may  have  them  as  a  defense  in 
case  the  purity  of  the  water  is  impugned. 

Plumbing  of  the  Milk  Plant. — The  plumbing  of  the  building  is  im- 
portant. Sanitary  open  plumbing  should  be  used  and  the  workmanship 
should  be  first-class.  The  fixtures  should  be  conveniently  placed  but 
toilets  should  not  open  off  rooms  in  which  milk  is  handled.  The  system 
should  be  designed  in  such  a  way  that  there  will  be  little  trouble  from 
freezing.  Pipes  should  be  wrapped  to  prevent  them  from  freezing  or  in 
the  case  of  long  leads  of  hot  water  piping,  to  prevent  loss  of  heat.  Fix- 
tures should  be  properly  trapped  and  the  main  soil  pipe  should  be  carried 
up  through  the  roof  above  the  ridge. 

The  wash  bowls  may  be  of  marble,  porcelain  or  of  enamel  ware.  The 
sinks  in  which  bottles  and  tinware  are  washed  are  generally  of  galvanized 
steel.  Wood  and  soapstone  are  absorptive  and  so  should  not  be  used.  In 
the  smaller  dairies  of  the  better  class  porcelain  sinks  are  sometimes  used 
for  washing  bottles.  .  They  are  expensive  but  otherwise  they  are  excellent. 

Cost  and  Equipment  of  the  Milk  Plant. — In  construction  it  should  be 
borne  in  mind  that  the  plant  should  perform  its  function  efficiently  and  at 
low  cost.  The  dealer  who  erects  an  unnecessarily  expensive  plant 
imposes  a  burden  on  the  business  in  the  same  way  that  the  producer 
does  who  builds  a  highly  expensive  barn.  The  land  chosen  for  a  site 
should  not  be  overvaluable.  The  building  itself  should  be  planned  with 
a  view  to  the  future  of  the  business;  it  should  be  so  designed  that,  as  con- 
venient, additions  can  be  made  and  it  should  be  durable  and  perfectly 
sanitary. 

U.  S.  Department  of  Agriculture  Milk  Plant  Score  Card. — A  correct 
conception  of  the  essential  features  of  a  first-class  plant  is  best  obtained 
by  studying  the  score  card  for  city  milk  plant  inspection,  of  the  dairy 
division  of  the  U.  S.  Department  of  Agriculture. 


248 


CITY  MILK  SUPPLY 
MILK  PLANT  SCORE  CARD 


Score 


Equipment 


Per- 
fect 


lowed 


Methods 


Score 


Per- 
feet 


Al- 
lowed 


Building: 
Location:   Free  from  contaminating 
surroundings 


Arrangement. 


Separate  receiving  room 1 

Separate  handling  room 2 

Separate  washroom 1 

Separate  sales  room 1 

Separate  boiler  room 1 

Separate  refrigerator  room.  .  .  . 

Construction 

Floors  tight,  sound,  cleanable.  .    2 
Walls  tight,  smooth,  cleanable 
Ceilings  smooth,  tight,  cleanable 

Drainage 2 

Floors 1 

Sewer  or  septic  tank 1 

Provision  for  light 2 

(10  per  cent,  of  floor  space.)-  • 

Provision  for  pure  air 2 

Screens 1 

Minimum    of    shafting,    pulleys, 
hangers,  exposed  pipes,  etc. .   1 

Apparatus 

Boiler 2 

(Water  heater,  1.) 
Appliances  for  cleansing  utensils 

and  bottles 2 

Sterilizers  for'bottles,  etc 2 

Bottling  machine 1 

Capping  machine 1 

Wash  bowl,  soap,  and  towel  in 

handling  room 1 

Condition 6 

Milk-handling  machinery 3 

Pipes,  couplings,  and  pumps.  .  .   2 

Cans 1 

Laboratory  and  equipment 

Water  supply 

Clean  and  fresh 1 

Convenient  and  abundant...       .    1 


12 


15 


Total »..  40 


Building: 

Cleanliness: 

Floors 

Walls 

Ceilings 

Doors  and  windows 

Shafting,  pulleys,  pipes,  etc 

Freedom  from  odors 

Freedom  from  flies 

Apparatus 

Cleanliness: 

Thoroughly  washed  and  rinsed. 
Milk-handling  machinery. . . 

Pipes,  cans,  etc 

Sterilized  with  live  steam 

Milk-handling  machinery. .  . 

Pipes,  cans,  etc 

Protected  from  comtamination 

Bottles 

Thoroughly  washed  and  rinsed. . . 

Sterilized  with  steam  15  min 

Inverted  in  clean  place 

Handling  milk 

Received  below  50°F 

(50°  to  55°,  2.) 
(55°  to  60°,  1.) 

Rapidity  of  handling 

Freedom  from  undue  exposure  to 

air 

Cooling 

Promptness 

Below  45°F 

(45°  to  50°,  1.) 

Capping  bottles  by  machine 

Bottle  top  protected  by  cover. . . 

Storage;  below  45°F 

(45°  to  50°,  3;  50°  to  55°,  1.) 

Protection  during  delivery 

(Iced  in  summer.) 

Bottle  caps  sterilized 

Inspection 

Bacteriological  work 

Inspection    of    dairies  supplying 

milk 

(2  times  a  year,  2;  once  a  year,  1. 

Miscellaneous , 

Cleanliness  .of  attendants 

(Personal  cleanliness,  1;  clean, 

washable  clothing,  1.) 
Cleanliness  of  delivery  outfit 


Total 60 


14 


Score  for  equipment plus  score  for  methods equals  total  score. 


NOTE. — If  the  conditions  in  any  particular  are  so  exceptionally  bad  as  to  be  inadequately  expressed 
by  a  score  of  '"0"  the  inspector  can  make  a  deduction  from  the  total  score. 


THE  MILK  CONTRACTOR  249 

It  allows  40  points  for  equipment  and  60  points  for  methods.  This 
estimate  of  the  relative  importance  of  the  two  is  instructive  and  should  be 
taken  to  heart  by  all  managers  of  milk  plants.  There  are  too  many  who 
feel  that  a  fine  building  equipped  with  expensive  apparatus  will  turn  out  a 
clean  safe  milk  without  any  particular  effort  on  their  part  to  insure  its 
doing  so.  The  fact  is  that  unless  the  building  is  kept  scrupulously  neat 
and  the  apparatus  perfectly  clean  and  sterile  and  unless  the  milk  is  han- 
dled properly  it  is  likely  to  be  the  worse  for  the  treatment  it  receives.  The 
apparatus  needs  particular  attention ;  it  is  somewhat  complicated  and  the 
milk  naturally  sticks  to  it  so  that  unless  the  utmost  vigilance  is  exercised 
it  is  bound  to  become  unclean.  Milk  picks  up  germs  from  whatever  it 
comes  into  touch,  so  that  dirty  apparatus  seeds  it  with  bacteria.  Undue 
exposure  to  the  air,  especially  if  it  is  dusty,  does  likewise.  If  in  addition 
the  milk  is  not  promptly  handled  and  cooled,  the  bacteria  have  an  excel- 
lent opportunity  to  grow  and  spoil  the  milk.  Elaborate  equipment  does 
not  necessarily  mean  excellent  or  even  good  milk,  as  many  health  officers 
have  learned  to  their  sorrow,  from  having  to  wrestle  with  big  expensive 
plants  that  owing  to  indifferent  management  turn  out  a  mediocre  product. 
The  contractor  who  expects  his  milk  plant  to  run  itself  is  foredoomed  to 
failure.  As  the  committee  on  Milk  Plant  Inspection  of  the  International 
Association  of  Dairy  and  Milk  Inspectors  puts  it,  "  attractive,  well- 
equipped  plants  are  no  indication  of  the  quality  of  milk  that  is  being  sold  ; 
the  milk  going  through  the  plant  must  be  of  good  quality  to  begin  with 
and  must  be  handled  properly." 

Under  equipment,  the  card  allows  21  points  for  building  and  con- 
struction and  15  points  for  apparatus.  For  the  building  reinforced-con- 
crete  construction  is  excellent.  The  walls  and  ceilings  should  preferably 
be  of  tile  or  brick;  they  should  be  sheathed,  made  dust  proof  and  painted 
a  light  color  if  these  materials  are  not  used.  The  window  space  should  be 
at  least  10  per  cent,  and  ought  to  be  20  per  cent,  of  the  floor  space.  Pro- 
vision should  be  made  for  screening  the  windows  and  outside  doors;  the 
latter  should  have  automatic  closing  devices.  Throughout  the  plant  the 
ceilings  and  walls  should  be  smooth,  tight  and  cleanable.  Window  sills, 
projecting  window  frames,  door  frames  and  other  places  where  dust  can 
settle  are  objectionable.  As  in  handling  the  milk,  more  or  less  is  spilled 
on  the  floors  and  as  in  cleaning  much  water  is  flowed  over  them  it  is  im- 
portant that  cement  or  some  other  impervious  material  should  be  used  in 
their  construction.  Iron  plates  set  flush  in  cement  give  good  satisfaction. 
The  plates  should  be  used  wherever  cans  are  rolled  about  much.  Care 
should  be  exercised  to  keep  the  floors  free  from  cracks  because  the  wash- 
ings accumulate  sour  milk  and  filth  in  them;  sometimes  considerable 
drainage  escapes  through  them  and  creates  beneath  the  floor  a  rather 
extensive  stinking  area.  Floors  should  be  sloped  from  the  walls  to  a  drain 
in  the  center  which  should  be  trapped  and  carried  to  the  public  sewer,  a 


250  CITY  MILK  SUPPLY 

filter  bed  or  septic  tank.  Small  plants  can  usually  be  ventilated  by  win- 
dows; large  ones  may  need  some  system  of  artificial  ventilation.  In  any 
plant  it  is  desirable  to  conduct  the  different  operations  in  separate  rooms 
but  in  the  smallest  this  is  impossible.  Even  in  these  a  separate  room 
for  handling  the  milk  is  a  necessity.  It  should  be  located  away  from  the 
ashes  and  soot  of  the  boiler  room  and  be  so  built  that  it  can  be  closed 
tightly  to  keep  out  steam  and  air  vitiated  with  odors  and  dust.  When  the 
room  is  in  use  no  one  whose  presence  is  not  absolutely  needed  should  be 
allowed  in  it. 

Large  plants  should  be  completely  equipped  with  apparatus  but  small 
ones  cannot  be.  In  general,  proper  equipment  for  a  plant  includes :  steam 
boiler,  appliances  for  cleaning  the  utensils  and  bottles,  sterilizers  for 
bottles  and  other  apparatus,  bottling  and  capping  machines,  proper  pip- 
ing, shafting,  etc.  for  operating  the  plant,  and  washbowl,  soap  and  towels 
for  attendants  in  the  milk-handling  room. 

All  weigh  cans,  storage  vats  and  other  apparatus  should  be  constructed 
of  suitable  metal,  preferably  tinned  copper.  Closely  fitting  covers  of 
material  similar  to  the  apparatus  should  be  provided  and  all  angles  and 
joints  should  be  soldered  smooth. 

Pipes  and  pumps  should  be  of  sanitary  construction  and  so  arranged 
that  they  may  be  easily  taken  apart  for  cleaning.  No  tightly  soldered 
elbow  joints  should  be  allowed. 

Valves  on  bottling  machines  should  be  simple  and  so  constructed  that 
they  may  be  easily  taken  apart  and  cleansed.  Especially  it  is  essential 
that  the  rubber  valve  seats  shall  be  easily  detachable. 

Every  milk  plant  should  be  equipped  with  a  Babcock  tester  and  large 
ones  should  have  laboratories  for  chemical  and  bacteriological  work. 

Two  points  are  allowed  for  laboratory  and  two  for  water  supply. 
Under  methods,  the  card  gives  14  points  for  cleanliness  of  the  building,  14 
for  cleanliness  and  sterilization  of  apparatus  and  bottles  and  22  points 
for  proper  handling  of  the  milk.  Besides,  4  points  are  allowed  for  clean- 
liness of  the  attendants  and  delivery  outfit,  3  for  bacterial  work  and  3  for 
inspection  of  dairies.  A  dirty  building  will  become  malodorous  and 
attract  vermin;  if  it  becomes  grossly  unclean  the  dust  and  dirt  may  con- 
taminate the  milk.  It  is  highly  important  that  apparatus  be  clean  and 
sterile,  otherwise  bacterial  pollution  of  the  milk  is  bound  to  result. 
Apparatus  is  properly  cleaned  by  first  washing  it  in  cool  water,  then  in 
hot  water  and  washing,  powder,  then  in  a  rinse  of  clean  hot  water,  after 
which  the  apparatus  should  be  sterilized  with  steam  or  if  that  be  lacking 
in  boiling  water.  Pumps  and  piping  are  washed  by  pumping  water 
through  them  right  after  they  are  thrown  out  of  service,  after  which  they 
are  taken  apart  for  thorough  cleansing  and  for  sterilization.  Rusted  and 
battered  apparatus  cannot  be  cleaned  and  should  be  discarded.  In  case 
a  milk  plant  is  putting  out  milk  of  inferior  quality  to  what  might  be  ex- 


THE  MILK  CONTRACTOR  251 

pec  ted  of  the  dairies  that  supply  it,  an  inspector  is  justified  in  having  all 
apparatus  taken  apart  for  thorough  inspection.  The  law  should  require 
milk  plants  to  be  equipped  with  apparatus  for  sterilizing  bottles ;  so  many 
epidemics  have  been  caused  by  infected  milk  bottles  that  there  should  be 
no  dallying  with  this  question.  Milk  may  be  spoiled  in  the  handling  of  it. 
The  temperature  at  which  it  arrives  at  the  plant  is  important;  the  card 
allows  3  points  for  milk  below  50°F.  and  less,  for  milk  between  this  tem- 
perature and  60°  above  which  point  nothing  is  given.  The  milk  should  be 
handled  rapidly.  The  cans  of  milk  should  not  be  permitted  to  stand  long 
on  the  receiving  platforms  or  in  the  plant  before  mixing,  pasteurizing,  etc. 
If  the  milk  is  not  pasteurized  directly  after  standardizing  it  should  be  held 
in  tanks  jacketed  with  ice  water  or  brine.  Only  the  larger  plants  can 
afford  bacteriological  laboratories  but  even  the  smaller  ones  can  have 
inspection  of  the  dairies  supplying  the  milk. 

Medical  Inspection  of  the  Employees. — The  importance  of  the  attend- 
ants is  beginning  to  be  appreciated.  It  is  not  enough  that  they  be  merely 
good  laborers;  besides,  they  must  have  sound  health,  be  clean  and  have 
decent  habits.  The  menace  that  those  who  handle  food  may  be  to  the 
public  has  only  been  recognized  within  the  last  decade  for  only  within 
that  time  has  it  been  appreciated  that ;  walking  cases  of  communicable 
diseases  are  not  rare,  and  the  part  played  by  bacillus  carriers  in  spreading 
infection  has  been  understood.  In  New  York  City  in  1915  a  law  was 
enacted  requiring  that  persons  engaged  in  handling  foods  should  hold  a 
certificate  of  health  from  the  health  department  of  the  city.  In  the 
medical  examination  of  these  persons  several  carriers  were  detected  and 
certificates  were  withheld  from  them.  Other  cities  have  adopted  similar 
laws  and  it  is  certain  that  as  their  importance  becomes  understood  their 
enactment  will  become  general. 

The  Bureau  of  Animal  Industry  in  1915  sent  out  1,250  questionnaires 
to  the  health  officials  of  cities  of  the  United  States  having  a  population  of 
5,000  or  more  and  received  replies  from  about  one-half  of  them.  To  the 
question 

"Do  you  require  any  systematic  medical  inspection  of  persons  employed  in 
milk  plants,  creameries,  cheese  factories,  ice-cream  factories  and  condenseries?" 

46  replied  yes  and  473  no.  A  sick  attendant  may  infect  the  milk  by 
sneezing  into  it,  the  fine  spray  of  his  sputum  carrying  the  germs  or  he 
may  infect  it  with  his  fingers  which  if  unclean  may  carry  nasal,  buccal, 
urinary,  or  fecal  discharges.  Therefore,  employees  should  be  taught  the 
danger  of  droplet  infection  and  of  unclean  hands.  Those  who  from  severe 
colds  or  other  causes  are  having  violent  coughing  spells  should  be  excused 
from  duty  while  any  employee  with  a  chronic  cough  should  be  subjected 
to  medical  examination  to  make  sure  that  he  is  not  consumptive.  The 
work  of  Coues  suggests  that  the  laborers  in  milk  plants  are  prone  to  develop 


252  CITY  MILK  SUPPLY 

sore  throats,  but  his  data  does  not  indicate  that  these  throats  are  in  any 
way  dangerous  to  milk  consumers.  However,  some  sore  throats  are  so, 
for  they  may  in  reality  be  diphtheritic  or  of  an  infectious  streptococcal 
nature.  Diphtheria  is  certainly  carried  by  milk  and  there  is  some 
evidence  to  indicate  that  employees  of  milk  plants  who  were  working 
when  they  had  septic  sore  throat  infected  the  milk  with  that  disease. 
So,  even  mild  throat  affections  may  be  of  importance  and  need  attention. 

Some  of  the  certified  dairies  pay  a  good  deal  of  attention  to  the  health 
of  their  employees.  Campbell  states  that  the  certified  dairies  around 
Chicago  began  the  medical  inspection  of  their  employees  in  November, 
1912,  and  since  then  employees  coming  into  contact  with  the  milk  have 
been  examined  at  least  once  a  month,  except  during  the  recent  epidemic 
of  aphthous  fever  when  other  arrangements  had  to  be  made.  Only  those 
who  have  been  vaccinated  are  employed.  Applicants  for  employment 
are  questioned  as  to  recent  illness,  as  to  whether  they  have  had  diphtheria, 
typhoid  fever,  or  are  subject  to  frequent  tonsillitis.  They  are  also  asked 
whether  they  have  recently  been  in  contact  with  a  sick  person.  Each 
applicant  is  examined  for  disease  of  the  eyes,  skin  of  the  face,  neck,  arm 
and  hands  and  the  condition  of  the  finger  nails  is  noted.  He  is  also  given 
a  careful  physical  examination  for  tuberculosis.  Applicants  showing  signs 
of  conjunctivitis,  tuberculosis,  syphilis  or  other  venereal  diseases,  or  any 
suppurative  process  or  any  disease  of  an  infectious  character,  are  rejected. 

A  card  index  of  every  employee  on  each  farm  is  kept;  the  points  re- 
corded are  the  replies  to  27  questions  and  the  findings  of  physical  exami- 
nations. A  separate  card  index  is  kept  of  the  monthly  medical  examina- 
tion; 10  items  are  recorded,  among  them  being  the  temperature,  pulse, 
condition  of  the  eyes,  of  the  skin  and  of  the  throat. 

Since  November,  1912,  775  primary  medical  examinations,  1,975 
medical  examinations  and  315  throat  cultures  have  been  made.  Of  the 
primary  examinations  38  per  cent,  were  of  persons  of  foreign  birth. 

In  most  milk  plants  the  superintendent  has  to  rely  on  the  uncertain 
method  of  accepting  the  man's  own  opinion  as  to  whether  he  is  fit  to  work 
or  not.  Typhoid  and  paratyphoid  fevers  are  the  communicable  diseases 
most  likely  to  be  spread  through  the  urine  and  feces.  With  these  mala- 
dies, too,  symptoms  may  be  misleading  or  lacking  so  that  the  mildly  sick 
do  not  attract  attention  and  continue  at  work  till  the  route  is  plainly 
infected  which  usually  leads  to  their  discovery.  Also,  there  are  carriers 
of  diphtheria  and  probably  of  scarlet  fever.  So,  every  effort  should  be 
made  to  reduce  as  far  as  may  be  the  danger  from  these  diseases -by  in- 
structing the  employees  as  to  the  infective  nature  of  the  several  dis- 
charges and  by  teaching  them  to  keep  their  hands  away  from  their  faces 
and  to  wash  after  using  the  toilet.  It  is  also  important  that  they  be 
made  to  understand  that  the  milk  should  not  come  into  contact  with  the 
hands;  probably  most  of  the  men  exercise  proper  care  in  this  matter  but 


THE  MILK  CONTRACTOR  253 

some  do  not  and  they  should  be  corrected  for  their  carelessness.  It 
should  be  clearly  understood  that  since  the  bottling  and  capping  of  milk, 
except  when  it  is  pasteurized  in  the  bottle,  is  done  subsequent  to  pasteur- 
ization there  is  opportunity  for  the  milk  to  be  infected  by  employees  after 
it  is  pasteurized.  Since  the  use  of  labor-saving  devices  reduces  the  num- 
ber of  employees  in  the  plant  it  also  reduces  somewha't  the  chance  of 
infection  from  the  help. 

Platforms. — While  the  receiving  and  loading  platforms  are  allowed  no 
points  on  the  score  card  they  are  nevertheless  important  for  the  efficient 
and  economical  management  of  the  plant  requires  that  they  be  of  ample 
size,  well-placed  and  kept  in  good  order.  It  is  likewise  important  that  the 
approaches  to  them  be  spacious  so  that  the  wagons  and  trucks  may  come 
and  go  without  crowding  and  confusion.  The  layout  of  the  plants  deter- 
mine the  location  of  the  platforms.  In  some  plants  a  single  platform 
running  the  full  length  of  the  building  is  used,  the  empty  cans  and  bottles 
being  left  at  the  end  near  the  receiving  vats  or  elevator  and  washroom 
while  the  delivery  wagons  are  loaded  from  the  cold  storage  rooms  at  the 
other  end.  In  other  plants  at  the  rear  there  is  a  receiving  platform  where 
the  milk  is  brought  and  where  empty  cans  and  bottles  are  left,  while  near 
the  cold  storage  room  is  a  loading  platform. 

Inspection  of  Plant. — In  inspecting  city  milk  plants  all  of  the  milk 
entering  them  should  be  tested  as  to  temperature  and  cleanliness  and  it 
should  be  sampled  for  bacteriological  and  chemical  analyses.  All  appa- 
ratus, piping,  pumps,  etc.,  should  be  examined  to  see  that  everything  is 
clean  and  in  working  order.  The  inspector  should  see  that  floors,  walls 
and  ceilings  are  clean ;  that  in  fly  time  the  building  is  properly  screened ; 
that  milk  is  handled  with  reasonable  rapidity;  that  it  is  not  unduly  ex- 
posed to  the  air;  that  the  milk  is  properly  cooled  and  is  stored  at  a  tem- 
perature not  above  45°F. ;  that  attendants  are  personally  clean  and  healthy 
and  are  wearing  clean  washable  clothing;  that  delivery  outfits  are  clean 
and  that  the  milk  is  properly  protected  during  delivery.  Only  covered 
delivery  wagons  should  be  permitted  and  all  milk  should  be  iced  in  hot 
weather.  The  temperature  of  the  milk  should  not  be  allowed  to  rise 
above  50°F.  Bacteria  samples  should  be  taken  at  frequent  intervals 
from  milk  on  the  delivery  wagons  to  check  up  the  work  of  the  plant. 
City  milk  plants  should  operate  only  under  a  revocable  license  system. 

The  inspection  is  defective  unless  a  good  system  of  records  thereof  is 
kept.  Records  should  include  application  for  permits  to  operate,  copies 
of  all  scores  and  of  all  analyses  made. 

Age  of  Milk  on  Arrival  at  Plant. — The  age  of  the  milk  when  it  reaches 
the  milk  plant  varies.  In  country  plants,  since  there  is  usually  but  one 
delivery  a  day,  the  evening  milk  is  about  12  hr.  and  the  morning  1  to  6 
hr.  old.  In  city  plants  the  age  of  the  milk  from  the  various  shipping 
points  is  very  different,  that  arriving  from  a  distance  or  over  lines  afford- 


254  CITY  MILK  SUPPLY 

ing  poor  service  being  much  older  than  that  from  nearby  stations.  The 
U.  S.  Department  of  Agriculture  in  1914  found  that  the  extremes  in  the 
age  of  the  milk  were  2  to  40  hr.  in  Washington,  4  to  16  hr.  in  Baltimore, 
4  to  41  hr.  in  Philadelphia,  2  to  48  hr.  in  Boston  and  4  to  40  hr.  in  Pitts- 
burgh. The  average  age  of  the  milk  in  the  several  cities  is  considerable 
under  the  maxima  given.  It  is  considerably  higher  in  Philadelphia, 
Boston  and  Pittsburgh  than  in  Washington  and  Baltimore  because  to  the 
first  three  of  these  cities  the  milk  comes  from  a  greater  distance  and  also 
because  much  of  it  goes  through  country  milk  plants.  In  Washington 
and  Baltimore  the  refrigerating  facilities  in  transit  are  poorer  than  they 
are  for  the  other  cities,  hence  the  milk  has  to  be  fresher.  In  Philadelphia 
practically  all  of  the  milk  is  less  than  30  hr.  old  on  arrival.  In  Boston  the 
milk  that  was  48  hr.  old  was  but  part  of  the  supply  of  a  single  dealer. 

In  considering  the  age  of  milk  it  must  be  remembered  that  it  is  im- 
portant, only  because  milk  spoils  as  it  grows  old.  Milk  that  is  24  hr.  old 
is  expected  to  be  more  decomposed  than  that  12  hr.  old  but  in  fact  this  is 
not  always  so.  The  decomposition  of  milk  is  effected  by  living  or- 
ganisms over  which  man  has  a  certain  amount  of  control  for  by  taking 
pains  he  can  limit  the  number  that  get  into  milk  and  by  cooling  it  suffi- 
ciently he  can  arrest  their  growth  and  so  retard  the  decomposition  of  the 
milk  or  in  a  sense  prevent  its  ageing.  A  dirty  milky  shipped  in  dirty  cans, 
in  a  poorly  iced  car  may  age  more  in  12  hr.  than  a  clean  milk,  in  clean  cans, 
in  properly  cooled  cars  may  in  16. 

Tasting  the  Milk. — When  milk  is  delivered  in  bulk  at  the  plant  for 
preparation  for  the  market,  it  is  usually  tasted  and  often  is  sampled  to 
determine  the  sediment,  the  butterfat  and  perhaps  the  bacterial  content. 
Some  tasters  take  the  milk  into  the  mouth;  others  simply  shake  the  cans 
vigorously  and  removing  the  cover  quickly,  take  the  odor.  By  either 
method  unpleasant  flavors  and  high  acidity  are  detected  with  consider- 
able certainty.  Milk  that  is  found  off  flavor  is  rejected;  thus  dealers  are 
protected  from  complaining  customers  and  from  paying  for  milk  that  is 
unsaleable.  Still,  because  bacterial  growths  develop  in  the  milk  after  it 
has  passed  the  tasters,  it  sometimes  reaches  the  consumer  with  a  disagree- 
able flavor.  In  the  past,  certain  abuses  were  common  in  tasting  and  sam- 
pling the  milk.  Tasters  drank  from  the  cans  or  their  covers,  or  tasted 
from  spoons  or  ladles  that  without  washing  were  used  to  stir  and  taste 
other  cans;  milk  in  the  cans  was  in  one  way  or  another  brought  into 
contact  with  the  hands  and  other  insanitary  practices  were  indulged  in. 
Nowadays  this  sort  of  thing  does  not  occur  in  the  better  plants  but  else- 
where it  still  persists. 

Drip  Pans. — After  the  cans  of  milk  have  been  tasted  and  sampled 
they  are  dumped  into  the  mixing  vats,  and  the  cans  inverted  over  a  drip 
pan  so  that  the  drainage  may  be  caught  and  saved  to  be  used  in  dairy 
manufactures. 


THE  MILK  CONTRACTOR  255 

Washing  of  Cans. — In  some  plants  the  cans  are  returned  unwashed 
to  the  farmer  which  is  a  very  short-sighted,  pernicious  practice  because 
few  dairy  farmers  have  the  facilities  for  properly  cleaning  them  and  tests 
show  that  the  bacterial  contamination  that  results  from  the  use  of  inster- 
ile  cans  is  serious.  For  instance,  the  U.  S.  Department  of  Agriculture 
found  that  cans  which  received  only  the  ordinary  washing  and  rinsing 
contained  from  300,000  to  18,000,000  bacteria  per  cubic  centimeter  with 
an  average  of  46,000,000.  So  10  gal.  of  milk  put  in  one  of  these  cans 
would  have  received  an  initial  contamination  of  100,000  bacteria  per 
cubic  centimeter.  Pease,  from  an  extensive  study  in  New  York  State, 
became  convinced  that  insterile  cans  were  important  factors  in  producing 
the  high  bacterial  counts  in  the  milk  of  New  York  City  in  summer.  A 
milk  plant  letter  of  the  U.  S.  Department  of  Agriculture  tells  of  one  milk 
dealer  who,  on  finding  that  the  cans  washed  in  his  plant  contained  as 
high  as  20,000,000  bacteria,  installed  a  more  efficient  washing  machine 
with  the  result  that  the  bacteria  were  cut  down  to  less  than  200,000  per 
can;  moreover,  undesirable  bacterial  forms  that  survived  the  old  process 
were  killed. 

In  small  plants,  cans  are  cleaned  by  hand.  Where  the  washing  is 
properly  done,  they  are  first  rinsed  in  cold  water,  then  scrubbed  in  hot 
water  with  washing  powder  and  finally  washed  in  clean  hot  water  and 
steamed  with  live  steam  if  it  is  available.  In  larger  establishments  a  jet 
machine  which  successively  forces  sprays  of  cold  water,  hot  water  and 
steam  into  the  cans  is  used.  This  ought  to  be,  and  in  many  plants  actu- 
ally is,  followed  by  a  blast  of  dry  air  to  dry  out  the  cans  so  that  neither 
moist  surfaces  nor  a  puddle  will  be  left  in  the  can  wherein  bacteria  will 
multiply  and  also  to  keep  the  cans  from  rusting.  Another  style  of  washing 
machine  brushes  out  the  can  with  hot  water  and  washing  powder  after 
which  the  cans  are  rinsed  and  then  steamed  on  a  jet  machine.  Other 
effective  types  of  machines  are  in  use.  The  covers  are  washed  in  hot 
water  and  washing  powder,  rinsed  and  dried  and  put  in  the  sterile  cans. 
If  the  covers  are  not  put  in  the  cans  at  once  the  cans  should  be  inverted 
and  kept  in  a  clean  place  where  they  are  protected  from  dust,  flies  and 
other  contaminations.  Much  stress  is  laid  on  this  sterilization  of  the 
cans  and  the  drying  them  out  with  hot  air.  Where  this  is  properly  done 
it  is  undoubtedly  a  good  thing  but  in  some  plants  the  cans  are  hurried 
through  the  process  at  such  a  prodigious  rate  that  one's  doubts  as 
to  the  efficacy  of  cleaning  and  sterilizing  are  raised,  and  in  some  cases 
these  suspicions  are  not  allayed  by  taking  the  odor  of  the  inside  of  the  cans 
when  they  arrive  at  the  farm.  It  is  not  intended  to  criticize  the  principle 
of  cleaning  and  sterilizing  the  cans  at  the  plant,  for  doing  so  has  in  a  large 
measure,  corrected  a  flagrant  sanitary  dereliction,  for  the  custom  that 
formerly  obtained  of  returning  the  cans  in  an  unwashed  condition  to  the 
farm  was  indefensible,  but  it  is  desired  to  point  out  that  the  work  may  be 


256  CITY  MILK  SUPPLY 

so  rushed  that  it  fails  in  its  object.  A  device  that  will  insure  the  cans 
being  exposed  to  the  steam  for  a  measured  interval  of  time  is  needed. 

Dirt  in  Milk. — The  amount  of  dirt  that  is  found  in  milk  varies  a  great 
deal  according  to  whether  a  small-top  milk  pail  is  used  in  milking  and 
other  sensible  precautions  to  keep  the  dirt  out  are  taken.  Some  figures 
that  have  been  published  show  that  the  dried  sediment  in  the  milk  of 
seven  German  cities  varied  from  3.8  to  13.5  mg.  per  liter;  in  Copenhagen, 
Denmark,  the  milk  contained  from  1  to  13  mg. ;  in  certain  Norwegian 
cities  the  sediment  averaged  2.6  mg.:  in  Washington,  D.  C.,  some  samples 
contained  as  high  as  180  mg.  In  American  cities  the  amount  of  visible 
dirt  in  milk,  even  as  it  is  delivered  to  the  consumer,  is  often  very  great 
as  any  one  can  tell  for  himself  by  gently  lifting  the  bottle  and  examining 
the  bottom.  Evans  at  one  time  estimated  that  the  citizens  of  Chicago 
receive  25  tons  of  dirt  per  year  in  their  milk. 

Clarification  of  Milk. — The  cream  separator  is  often  used  to  clarify 
milk.  As  the  milk  passes  through  the  machine  practically  all  of  the  in- 
soluble dirt,  some  casein,  cellular  debris  from  the  udder  and  bacteria 
collect  as  a  slime  on  the  wall  of  the  separator  bowl.  The  separated  cream 
and  skim-milk  are  recombined  by  mixing  them.  In  many  instances  the 
process  has  given  satisfaction,  in  others  it  has  not.  In  passing  through 
the  separator  the  clusters  of  fat  globules  are  broken  up  and  to  some  extent 
the  globules  themselves  are  disrupted.  Consequently,  the  recombined 
milk  does  not  show  as  sharp  a  cream  line  as  the  untreated  milk  which  often 
leads  customers  to  complain.  The  bacterial  clumps  and  chains  are 
broken  by  the  passage  of  the  milk  through  the  separator  so  that  the 
recombined  milk  and  cream  has  a  higher  bacterial  count  than  the  un- 
separated  milk.  This  process  has  been  thought  to  injure  the  keeping 
qualities  of  the  milk  and  the  explanation  therefor  has  been  given  that 
as  individuals  the  bacteria  multiply  more  rapidly  than  in  aggregates. 
Such  an  explanation  is  theoretical  and  it  has  not  been  a  universal  experi- 
ence that  the  clarified  milk  fails  to  keep. 

Specially  constructed  machines  called  clarifiers  have  come  into  gen- 
eral use  in  large  milk  plants  for  removing  the  visible  dirt  from  milk;  be- 
sides this  they  abstract  mineral  salts,  casein,  cells  from  the  udder  and 
bacteria.  The  machines  depend  on  the  centrifugal  principle  but  the 
cream  is  not  separated  in  passing  through  them;  hence  the  clarified  milk 
creams  normally.  It  has  been  claimed  that  in  clarifying  by  these  ma- 
chines a  notable  removal  of  cells  and  bacteria  is  effected  and  that  the  milk 
is  greatly  improved  thereby.  Others  are  of  the  belief  that  the  numbers 
of  bacteria  in  the  milk  are  increased  by  breaking  up  the  clumps  and  chains 
of  the  organisms  and  that  the  keeping  quality  of  the  milk  is  impaired. 
It  is  the  author's  opinion  that  while  these  clarifiers  always  remove  large 
numbers  of  bacteria  and  cells  their  effect  on  the  bacterial  content  of  the 
milk  is  not  uniform,  the  numbers  being  sometimes  increased,  and  other 


THE  MILK  CONTRACTOR 


257 


times  decreased;  that  more  evidence  is  needed  as  regards  the  effect  of 
the  machine  on  the  keeping  quality  of  the  milk;  and  that  the  best  results 
are  obtained  when  clarification  is  followed  by  pasteurization.  It  is  also 
his  opinion  that  the  machines  do  greatest  service  in  removing  the  dirt, 
hairs,  and  blood,  which  even  under  cleanly  conditions  and  careful  man- 
agement get  into  milk  in  small  amounts  and  which  no  one  wishes  to  drink. 
The  objection  has  been  raised  to  these  machines  that  in  reality  they  are 
a  fraud  on  the  consumer  in  that  by  removing  the  visible  dirt  they  mislead 
him  into  the  belief  that  the  milk  has  never  been  contaminated.  This 
seems  an  extreme  position  to  take,  for  every  one  knows  that  it  is  impossi- 
ble to  collect  tons  upon  tons  of  milk  for  city  delivery  without  some  dirt 
accumulating  in  it,  and  on  esthetical  grounds.it  seems  best  to  remove  as 
much  of  it  as  possible.  If  the  clarifiers  show  an  unreasonable  amount  of 
dirt  the  remedy  is  to  trace  the  dirty  milk  back  to  the  country  and  shut 
the  dairymen  that  are  producing  it  out  of  the  city  till  they  are  prepared 

TABLE  76. — EFFECT  OF  CLARIFYING  MILK  ON  THE  BACTERIAL  AND  CELL  COUNTS 
(BOSTON  BIOCHEMICAL  LABORATORY) 
Machine  A  Working  at  6,000  r.p.m. 


Date 

Minutes 
elapsed 
after 
starting 
the  run 

Tempera- 
ture of 
milk  at 
sampling, 

Bacteria  per 
cubic 
centimeter 
in 
unclarified 
milk 

Bacteria  per 
cubic 
centimeter 
in 
clarified 
milk 

Average 
number 
of  cells  per 
field  in 
unclarified 
milk 

Average 
number 
of  cells  per 
field  in 
clarified 
milk 

May  14,  1915  

5 
25 
35 
45 
47 

20 
50 
65 
75 
85 
120 

20 
50 
60 
115 

20 
50 
80 
90 
100 
110 
115 

80 
80 
85 

72 
74 

80 
82 
78 
78 
83 
75 

76 
74 
106 
96 

98 
74 
80 

88 
78 
72 
78 

1,700,000 
1,250,000 
950,000 
780,000 

1,900,000 
920,000 
1,500,000 
1,200,000 
1,330,000 

17.0 
12.0 
17.0 
17.0 

9.0 
8.0 
4.0 
4.0 
13.0 

May  18,  1915  

Av.  1,170,000 
360,000 
710,000 
950,000 
800,000 
750,000 
900,000 

Av.  1,370,000 
360,000 
880,000 
960,000 
980,000 
850,000 
1,080,000 

Av.  15.7 
4.0 
4.3 
13.0 
8.0 
6.3 
3.2 

Av.     8.2 
2.2 
2.3 
3.4 
2.4 
1.2 
2.3 

May  19,  1915  ,  .  . 

Av.  7,400,000 
1,350,000 
1,600,000 
850,000 
950,000 

Av.    851,000 
1,220,000 
1,300,000 
420,000 
500,000 

Av.     6.5 
13.6 
6.8 
8.0 
7.0 

Av.     2.1 
6.0 
5.4 
4.0 
5.0 

May  20,  1915 

Av.  1,187,000 
410,000 
230,000 
600,000 
860,000 
660,000 
650,000 
750.000 

Av.    860,000 
270,000 
190,000 
580,000 
1,000,000 
500,000 
700,000 
610,000 

Av.     8.8 
7.0 
6.7 
27.6 
20.2 
18.2 
19.0 
17.0 

Av.     5.1 
4.0 
4.3 
10.5 
12.6 
12.0 
5.0 
1.0 

Av.      594,285 

Av.    550,000 

Av.  15.1 

Av.     7:1 

17 


258 


CITY  MILK  SUPPLY 


TABLE  76. — (Continued) 
Machine  B  Working  at  5,400  r.p.m. 


Date 

Minutes 
elapsed 
after 
starting 
the  run 

Tempera- 
ture of 
milk  at 
sampling, 
°F. 

Bacteria  per 
cubic 
centimeter 
in 
unclarified 
milk 

Bacteria  per 
cubic 
centimeter 
in 
clarified 
milk 

Average 
number 
of  cells  per 
field  in 
unclarified 
milk 

Average 
number 
of  cells  per 
field  in 
clarified 
milk 

May  14,  1915 

5 

78 

1,100,000 

650,000 

11  0 

3  0 

25 

79 

1,030,000 

820,000 

82.0 

2.0 

35 

85 

600,000 

1,010,000 

9.0 

5.0 

45 

84 

450,000 

900,000 

9.0 

1.0 

Av.      790,000 

Av.   845,000 

Av.  12.75 

Av.  2.75 

May  17,  1915  

20 

94 

1,070,000 

580,000 

8.0 

6  0 

60 

88 

780,000 

980,000 

11.0 

9.0 

75 

92 

800,000 

950,000 

17.0 

5.0 

80 

88 

1,150,000 

780,000 

4.0 

4.0 

85 

88 

850,000 

750,000 

4.0 

2.0 

90 

90 

900,000 

1,400,000 

24.0 

4.0 

Av.      925,000 

Av.    906,666 

Av.  12.5 

Av.     5.0 

May  19,  1915  . 

20 

92 

900  000 

800,000 

5  7 

1   i 

50 

88 

1,110,000 

910,000 

7.2 

3.0 

60 

90 

780,000 

660,000 

6.8 

3.0 

65 

94 

870,000 

930,000 

5.6 

2.2 

Av.      915,000 

Av.    825,000   !Av.     6.3 

Av.     5.0 

May  21,  1915  

20 

86 

200,000 

180,000 

14.5 

14.0 

50 

74 

90,000 

130,000 

14.0 

13.0 

70 

78 

280,000 

240,000 

13.0 

11.0 

85 

80 

130,000 

170,000 

14,7 

11.8 

95 

80 

550,000 

750,000 

19.0 

17.0 

105 

72 

760,000 

820,000 

22.0 

19.0 

Av.      335,000 

Av.    381,666 

Av.  16.2 

Av.  14.3 

TABLE  77. — RESULTS  OF  CHEMICAL  ANALYSIS  OF  CLARIFIER  SLIME  (BOSTON 

BIOCHEMICAL  LABORATORY) 

Machine  A 


Date 

Weight  in  grams 
of  samples  taken 
for  analysis 

Moisture, 
per  cent. 

Ash, 
per  cent. 

Fat, 
per  cent. 

Casein  on 
moist 
sample 

Casein  on 
dry 
sample 

May  18,  1915.... 

520 

66.96 

3.16 

3.09 

3.92 

0.96 

May  19 

280 

66  01 

3  36 

3  21 

3  91 

1  34 

May  20  

460 

66.66 

3.37 

2.09 

5.09 

1.73 

Average  

66.54 

3.29 

2.79 

3.97 

1.34 

Machine  B 


May  17. 

540 

69  32 

2  33 

3  75 

6  01 

1  84 

May  19  
May  21  
Average 

410 
440 

67.90 
68.25 
68  59 

2.57 
2.39 
2  43 

2.93 
2.59 
3  09 

5.30 
7.33 
1  21 

1.70 
2.30 
1.94 

THE  MILK  CONTRACTOR  259 

to  produce  clean  milk.  That  clarifiers  are  useful  seems  evident  from  their 
wide  adoption.  Through  the  courtesy  of  the  Boston  Biochemical  Lab- 
oratory there  are  presented  in  Table  76  data  showing  the  effect  of  clari- 
fication of  milk  as  exemplified  by  two  different  makes  of  clarifiers  and  in 
Table  77  analyses  of  clarifier  slime. 

Bahlman  showed  by  analysis  that  clarifier  slime  was  60  per  cent,  mois- 
ture and  40  per  cent,  solid  matter  and  that  it  carried  950,000,000  bacteria 
per  gram.  The  dried  slime  was  83.36  per  cent,  organic  and  14.64  per  cent, 
mineral  matter.  Dried  powdered  slime  contained  the  constituents  shown 
in  Table  78. 

TABLE  78.— CHEMICAL  ANALYSIS  OF  CLARIFIER  SLIME  (BAHLMAN) 

Protein  (N  X  6.38) 67.9    largely  casein. 

Fat 3.4    partly  derived  from  epithelial  cells   and 

other  organic  detritus. 

Milk  sugar 7.8    normal  milk  constituent. 

Crude  fiber 2.2 

Silica 3.8] 

Oxide  of  iron 0.5?  derived  from  earth  contamination. 

Oxide  of  aluminum 0 . 6  j 

Calcium  phosphate 3.6    a  normal  milk  constituent. 

Potassium  phosphate 6.2    a  normal  milk  constituent. 

Sodium  and  potassium  chlorides ...     0.1     a  normal  milk  constituent. 


96.1 

Undetermined . . . . v. 3.9     accounted  for  by  protein  factor  used,  and 

by  the  SiO2  and  Fe2O3  existing  in  the 
slime  as  hydrates, 

It  therefore  appears  that  the  residue  consists  very  largely  of  normal 
milk  constituents.  The  amount  of  material  removed  of  course  varies  in 
different  milks.  Bahlman  found  that  in  one  run,  in  which  725  gal.  of 
milk  passed  through  the  machine,  2.5  Ib.  of  slime  were  deposited  which  is 
1.6  grams  of  moist  slime  to  the  gallon.  He  concluded  that  though  large 
numbers  of  bacteria  were  contained  in  the  slime,  the  percentage  removal 
probably  was  not  great,  since  the  milk  is  exposed  to  the  separating  action 
for  only  a  brief  period. 

He  found  that  by  recentrifuging  clarified  milk  in  the  laboratory  for  a 
longer  time  and  at  a  lower  speed,  more  sediment  was  thrown  out  thus 
showing  that  the  clarifiers  do  not  remove  all  the  matter  that  it  is  possible 
to,  by  centrifugal  force. 

Hinkelman  by  passing  a  gallon  of  milk  on  the  verge  of  souring,  re- 
peatedly through  the  clarifier  was  able  materially  to  reduce  its  bacterial 
count  and  delay  its  souring  several  hours.  It  is  his  belief  that  bacteria 
of  different  species  are  of  different  weights  and  therefore  that  some  species, 
being  heavier  than  others,  in  the  process  of  clarification  separate  out  more 
completely.  From  experiments  he  has  made  he  concludes  that  strepto- 


260 


CITY  MILK  SUPPLY 


cocci,  staphylococci,  pneumococci,  diphtheria  and  typhoid  bacilli,  because 
of  their  greater  weight,  are  more  easily  thrown  out  by  centrifugal  action 
than  are  colon  bacilli  and  other  forms  that  occur  in  milk. 

Instead  of  using  bouillon  cultures,  as  Hinkelmann  did,  to  study  the 
action  of  milk  clarifiers  in  throwing  out  disease  germs,  McClintock 
used  milk  cultures,  with  the  results  shown  in  Table  79. 

TABLE  79. — ACTION  OF  MILK  CLARIFIERS  IN  THROWING  OUT  DISEASE  GERMS 

(McCLINTOCK) 


Bacteria 

B.   diphtherias 

B.  typhosus 

B.  coli 

Number  per  c.c. 
before  clarifica- 
tion of  milk  

400,000 

1,521,000 

2,520,000 

595,000 

460,000 

756,000 

946,000 

3,960,000  890,000 

Number  per  c.c. 
after  clarification 
of  milk  

17,000 

61,000 

75,000 

11,900 

5,000 

3,000 

5,800 

18,000      17,800 

Percentage  reduc- 
tion by  clarifica- 

95.8 

96.0 

97.1 

97.9 

99.0 

99.7 

99.4 

99  .  6          98  .  0 

Bacteria 

B.  subtilis 

St.  pyogenes 

Common  lactic  bacteria 

Number  per 
c.c.  before 
clarification 
of  milk  

7,280,000 

920,000 

641,000 

7,280,000 

920,000 

.641,000 

290,000 

460,000 

80,000 

7,381,000 

Number  per 
c.c.  after 
clarification 
of  milk  

70,000 

None 

6,000 

7,000 

None 

9,300 

260,000 

390,000 

70,000 

6,200,000 

Percentage 
reduction  by 
clarification 

99.9 

100.0 

99.1 

99.1 

100.0 

99.0 

10.4 

15.3 

12.5 

16.1 

The  percentage  reduction  of  pathogenic  forms  including  B.  coli  and 
B.  subtilis  is  remarkable,  whereas  the  percentage  reduction  of  the  lactic 
bacteria  is  comparatively  slight.  Thus  it  would  appear  that  milk 
clarifiers  have  a  selective  action  in  removing  disease  germs  from  milk. 
In  confirmation  of  this,  McClintock  made  further  tests  using  mixture 
of  disease  germs  and  lactic  bacteria  in  milk  and  found  that  95.8  to  99 
per  cent,  of  the  disease  germs  and  only  15.3  to  16.1  per  cent,  of  the 
lactic  bacteria  were  thrown  out. 


THE  MILK  CONTRACTOR  261 

Further  observations  will  be  necessary  before  definite  conclusions  as 
to  the  practical  value  of  this  action  of  clarifiers  can  be  reached  but  it 
seems  that  it  must  be  helpful  although  it  is  hardly  probable  that  re- 
liance can  be  placed  on  clarifiers  to  wholly  remove  disease  germs. 

Standardizing. — From  the  mixing  vats  the  milk  goes  to  the  standard- 
izing vats  where  it  is  brought  to  the  butterfat  content  that  the  contractor 
has  determined  the  milk  he  sells  shall  have.  Practically,  this  is  generally 
fixed  by  the  minimum  requirement  of  the  milk  ordinance  of  the  city  for 
butterfat.  Thus  if  the  code  establishes  3.2  per  cent,  as  the  minimum 
butterfat  content  of  whole  milk,  most  dealers  will  sell  milk  that  tests  3.3 
to  3.5  per  cent.,  whereas  if  3.5  per  cent,  is  the  standard,  milk  that  runs 
a  trifle  higher  in  butterfat  will  be  sold.  Since  the  milk  standards  of 
most  communities  are  set  so  low  that  the  milk  of  all  but  a  few  cows  can 
meet  them,  much  of  the  milk  delivered  at  the  milk  plant  carries  more 
•butterfat  than  the  law  stipulates  as  necessary,  and  standardization  of 
such  milk  means  lowering  the  butterfat  content  in  some  way.  On  the 
other  hand,  some  milk  that  is  low  in  butterfat  in  standardizing  has  the 
content  thereof  raised.  When  the  milk  of  a  herd  runs  close  to  the  set 
limit  a  little  richer  milk  or  cream  is  often  added  to  bring  the  herd  milk 
above  suspicion.  Also,  a  man  whose  herd  tests  but  3.5  per  cent,  may  wish 
to  market  4  per  cent,  milk  and  does  so  by  skimming  part  of  the  milk  he 
produces  and  adding  enough  cream  to  raise  the  test  to  the  desired  point 
while  the  skim-milk  is  used  by  feeding  it  to  his  stock.  The  laws  of  some 
communities  forbid  standardization  on  the  ground  that  it  upsets  the 
natural  ratio  between  the  butterfat  and  the  other  constituents  of  the 
milk  and  also  on  the  ground  that  the  cream  and  the  milk  which  are  added 
are  apt  to  be  older  than  the  milk  that  is  to  be  standardized  and  hence 
are  likely  to  increase  the  acidity  and  the  bacterial  count.  To  the  first 
of  these  objections  it  may  be  replied  that  the  ratio  of  butterfat  to  total 
solids  varies  considerably  in  the  different  breeds  of  cattle  and  that  there 
is  no  evidence  that  the  changing  of  the  ratio  by  standardization  is  in  any 
way  disturbing  to  the  health  of  the  great  bulk  of  milk  consumers.  The 
truth  of  the  other  allegation  must  be  admitted  but  it  is  for  the  interest 
of  the  dealer  to  use  fresh  milk  and  cream  in  standardizing  for,  if  he 
does  not,  the  keeping  quality  and  the  flavor  of  his  milk  is  likely  to  be 
impaired  so  that  the  danger  to  be  apprehended  from  this  source  is  less 
grave  than  might  be  expected.  As  a  matter  of  fact  the  public  is  prob- 
ably served  with  a  more  uniform  quality  of  milk  where  standardization  is 
practised  than  where  it  is  not.  So  the  wisdom  of  laws  prohibiting  stand- 
ardizing may  be  doubted  especially  as  they  do  not  appear  to  be  particularly 
beneficial  and  certainly  invite  evasion  and  encourage  deception,  because 
dairymen  see  no  harm  in  the  practice,  and  are  neither  going  to  run  the  risk 
of  prosecution  for  selling  milk  that,  although  it  normally  is  a  trifle  above 
what  the  law  requires  in  butterfat,  occasionally  falls  below  it,  nor  stand 


262  CITY  MILK  SUPPLY 

the  financial  loss  which  would  ensue  from  selling  milk  from  a  high-testing 
herd  in  competition  with  that  of  the  low-testing  herd  of  a  rival.  Detection 
of  the  violation  of  such  laws  is  not  easy  and  their  enforcement  is  difficult. 
Perhaps  it  might  be  required  to  mark  this  standardized  milk  as  "blended." 
In  some  cities  condensed  milk  is  used  in  standardizing;  the  author  would 
regard  this  as  an  adulteration.  It  is  said  that  milk  powder  is  extensively 
used  for  mixing  up  a  milk  to  be  used  in  blending  and  that  it  is  very  diffi- 
cult to  detect  this  practice. 

In  Copenhagen  the  richness  of  the  milk  is  plainly  marked  on  the  con- 
tainers and  the  price  of  milk  is  based  on  the  butterfat  content.  In  the 
United  States  this  policy  has  not  been  adopted;  it  seems  honest  for  it 
allows  the  consumer  to  pay  for  what  he  wants  and  can  afford.  Some  time 
it  may  be  adopted  here  but  it  is  easy  to  foresee  that  the  prejudice  of  cus- 
tom will  have  to  be  overcome  and  that  the  delivery  of  milk  of  several 
different  grades  from  one  wagon  presents  difficulties. 

Hinman  has  pointed  out  that  this  tendency  of  the  large  milk  contrac- 
tors to  supply  milk  of  uniform  butterfat  content  tends  to  eliminate  the 
effect  of  the  seasonal  changes  of  the  milk.  Normally  in  the  spring  when 
the  cows  go  from  grain  feeds  to  pasturage  there  is  a  drop  in  the  butter- 
fat  content  of  the  milk  which  is  followed  by  a  rise  to  a  point  somewhat 
above  the  summer  average  and  that  rise  is  succeeded  by  a  drop  to  mid- 
summer level  after  which  there  comes  another  rise  to  the  high  butterfat 
content  of  winter  and  concentrated  feeds.  Analysis  of  the  milk  sold  in 
Indianapolis  shows  that  in  contrast  to  this  condition  which  obtained 
from  1906  to  1910,  the  butterfat  from  1911  to  1913  remained  practically 
uniform  throughout  the  year. 

In  practice,  milk  is  standardized  by  either  increasing  or  decreasing 
the  percentage  of  butterfat  in  normal  milk.  It  may  be  increased  by 
adding  cream  or  a  richer  milk,  or  by  skimming  a  portion  of  the  milk  and 
returning  the  cream  obtained  to  the  rest.  The  butterfat  content  of  milk 
may  be  decreased  without  watering  the  milk,  by  adding  milk  poorer  in 
butterfat,  or  .skim-milk  or  by  skimming  part  of  the  normal  milk  and  add- 
ing the  skim-milk  to  the  remainder. 

Pearson  of  the  Cornell  University  Agricultural  Experiment  Station 
suggested  the  use  of  the  following  diagram,  a  rectangle  with  two  diag- 
onals, in  solving  problems  in  standardizing.  The  tests  of  the  milk  or 


25 


17 


creams  to  be  blended  are  written  in  the  left-hand  corners  and  the  desired 
test  in  the  center,  while  in  the  right-hand  corners  are  placed  figures  that 


THE  MILK  CONTRACTOR  263 

represent  the  difference  between  the  test  diagonally  opposite,  and  the 
desired  test  in  the  center.  Then  the  figure  in  the  upper  right-hand 
corner  indicates  the  required  amount  of  milk  or  cream  of  the  test  of  that 
in  the  upper  left-hand  corner,  and  the  figure  in  the  lower  right-hand  corner 
the  amount  required,  of  the  test  in  the  lower  left-hand  corner. 

Problem. — In  what  proportion  should  a  3  per  cent,  milk  be  mixed  with 
a  25  per  cent,  cream  to  get  a  20  per  cent,  cream  and  how  many  pounds 
of  each  would  be  necessary  to  make  75  Ib.  of  the  light  cream? 

Five,  the  difference  between  20  and  25,  and  17,  the  difference  between 
3  and  20,  indicate  respectively  the  number  of  parts  of  3  per  cent,  milk  and 
the  number  of  parts  of  25  per  cent,  cream  that  should  be  used  in  blending 
the  20  per  cent,  cream.  Having  determined  this  proportion,  the  quan- 
tities of  each  required  to  make  up  75  Ib.  of  the  light  cream  is  calculated 
as  follows : 

%2  X  75  =  17.04  Ib.  of  3  per  cent.  milk. 
x%2  X  75  =  57.96  Ib.  of  25  per  cent,  cream 
17.04  +  57.96  =  75 

Various  manuals  on  milk  testing  show  how  other  problems  can  be  solved 
in  a  similar  manner. 

Storage  in  Tanks. — After  standardization,  the  milk  is  ready  for  pas- 
teurization or,  if  that  process  is  omitted,  for  canning  or  bottling  but  if 
the  milk  is  not  used  at  once  it  is  stored  in  large  brine-jacketed  tanks  where 
it  is  held  at  a  temperature  sometimes  as  low  as  35°F.  until  needed.  The 
amount  of  milk  thus  held  for  use  is  sometimes  very  great;  in  one  of  the 
Philadelphia  milk  plants  there  are  four  steel  glass-lined  tanks  each  of 
which  has  a  capacity  of  20,000  gal. 

Preservation  of  Food  by  Heat. — From  primeval  times,  mankind  has 
applied  heat  to  food  in  order  to  make  it- palatable,  digestible  and  safe, 
but  for  only  the  past  century  and  a  half  has  he  heated  it  with  the  definite 
object  of  preserving  it.  Spallanzani  in  1765  boiled  meat  extract  for  an 
hour  in  hermetically  sealed  flasks  and  observed  that  thereafter  no  dis- 
integration of  the  extract  occurred.  In  1782  Scheele  advised  that  this 
principle  be  applied  to  the  preservation  of  vinegar  by  exposing  it  in 
bottles  to  the  temperature  of  boiling  water.  In  1804  Appert  of  Paris 
discovered  the  process  of  canning  and  in  1811  published  a  treatise  on 
"The  Art  of  Preserving  Animal  and  Vegetable  Substances."  Durand, 
in  England  in  1810,  took  out  a  patent  for  preserving  certain  foods  in  tins 
and  glass  jars.  In  1819-20  the  pioneer  canners  of  America,  Daggett, 
Kensett,  Underwood  and  Mitchell  made  the  small  beginnings  of  what 
has  since  developed  into  the  canning  industry.  All  of  these  men  worked 
empirically  because  the  preservation  of  food  by  heat,  depends  on  bacterio- 
logical principles  that  were  not  understood  till  the  researches  which  Louis 
Pasteur  carried  on  from  1860  to  1864,  on  the  " diseases  of  wine"  were 


264  CITY  MILK  SUPPLY 

completed.  He  found  that  by  heating  wine  to  temperatures  ranging 
from  122  to  140°F.  souring  and  other  undesirable  changes  could  be  pre- 
vented. The  process  has  proved  applicable  to  a  variety  of  foods  and 
has  been  called  in  honor  of  the  discoverer,  pasteurization.  It  may  be 
denned  as  the  process  of  checking  or  delaying  bacterial  decomposition 
of  food  and  other  substances,  by  exposing  them  to  heat  in  such  a  manner 
as  to  effect  a  partial  destruction  of  the  contained  germs,  leaving  alive 
only  those  that  are  in  the  spore  state  and  others  that,  though  they  sur- 
vive, bring  about  changes  in  the  substance  but  slowly  or  not  at  all. 
Pasteurized  foods  will  not  keep  indefinitely  for  usually  some  germs  in 
time  attack  them.  Pasteurization  is  to  be  carefully  distinguished  from 
sterilization  by  heat,  for  in  the  latter  process  such  high  temperatures  are 
used  that  both  the  germs  and  their  spores  are  killed.  Sterilization  as  a 
means  of  preserving  foods  is  severely  limited,  for  the  temperatures  used 
to  effect  it  are  so  high  that  many  foods  are  injured  to  such  a  degree  as  to 
be  unusable. 

Application  of  Pasteurization  to  Milk. — The  attempt  was  made  to 
sterilize  milk  for  human  consumption  but  it  was  found  necessary  to  heat 
it  for  a  long  time  at  212°F.,  or  to  higher  temperature  which  gave  the  milk 
a  decided  flavor,  caramelized  the  milk  sugar  and  otherwise  radically 
changed  it  so  that  the  public  would  have  none  of  it.  Pasteurization  has 
proved  applicable  to  milk  and  from  being  used  only  by  physicians  in  a 
limited  way  and  for  special  purposes  has  been  accepted  by  the  public 
and  is  practised  commercially  on  a  tremendous  scale. 

Soxhlet  in  1886  was  the  first  to  propose  the  use  of  heated  milk  in  infant 
feeding.  In  this  country  the  first  allusion  to  the  subject,  according  to 
Rosenau,  was  in  1889  by  Jacobi  who  had  long  used  heated  milk  in  his 
extensive  practice  as  a  pediatrician.  The  growth  of  the  use  of  pasteurized 
milk  was  gradual  for  practitioners  raised  objections  to  it  and  the  public 
was  suspicious  of  it  but  it  has  overcome  prejudice  and  established  itself. 

Progress  in  the  art  of  heating  milk  also  was  slow,  for  many  difficul- 
ties were  encountered  but  they  have  been  surmounted.  Three  principal 
methods  of  pasteurization  have  been  perfected,  namely:  (1)  the  flash, 
instantaneous  or  continuous;  (2)  the  holder,  holding,  held  or  discontinuous; 
and  (3)  in  the  bottle  or  in  final-package,  processes.  In  the  flash  method 
milk  is  exposed  for  from  a  few  seconds  to  perhaps  3  min.  at  temperatures 
of  from  175°  to  185°F.,  while  in  the  holder  method  temperatures  of  from 
140°  to  150°F.  are  used  and  the  exposure  is  usually  for  20  to  45  min. 
The  bottle  or  final-package  method  may  be  regarded  as  a  modification 
of  the  holder  process  and  the  temperatures  and  times  of  heating  are  about 
the  same.  The  bottling  of  milk  hot  which  has  been  proposed  by  Ayres 
and  Johnson  amounts  to  a  variation  of  the  bottle  method  and  is  in  the 
experimental  stage. 

The  dairy  industry  has  adopted  pasteurization  in  the  manufacture  of 


THE  MILK  CONTRACTOR  265 

butter  and  for  city  milk.  The  attempt  has  been  made  to  utilize  it  in 
cheese  making  but  so  far  with  only  limited  success. 

The  Danes  were  the  first  to  apply  pasteurization  in  butter  making. 
Acting  on  Storch's  discovery  in  1890,  that  the  flavor  of  butter  could  be 
changed  and  consequently  controlled  by  the  addition  of  different  kinds 
of  bacteria  to  ripening  cream,  they  adopted  the  use  of  starters  in  butter 
making.  The  starter  is  prepared  with  certain  precautions  by  growing 
a  known  mixture  of  bacteria  in  milk  that  has  been  heated  nearly  to  boiling 
and  when  ready  is  used  to  inoculate  the  cream  which  is  either  obtained  from 
pasteurized  milk  or  is  itself  pasteurized.  The  Danes  used  the  flash  proc- 
ess of  pasteurization  and  adopted  185°F.  as  the  legal  minimum  because 
the  studies  of  Bang  in  1894  showed  that  the  B.  tuberculosis  is  killed  at 
that  temperature  and  because  he  persuaded  them  to  protect  their  young 
stock  from  this  and  other  diseases  by  enacting  a  law  in  1898,  requiring 
that  all  skim-milk  should  be  pasteurized  before  being  returned  to  the 
farm.  The  Danes  were  so  very  successful  in  the  London  and  other 
markets,  with  their  butter  made  from  pasteurized  cream  that  the  process 
of  manfacture  was  gradually  adopted  by  others  and  now  in  the  United 
States  and  elsewhere  many  buttermakers  are  using  it. 

Various  difficulties  that  arise  in  the  manufacture  of  cheese  are  of 
bacterial  origin  so  that  it  would  seem  that  the  pasteurization  of  the  milk 
which  is  used  might  be  helpful  but  it  has  not  proved  so  because  of  two 
difficulties  that  are  encountered,  to  wit:  that  heated  milk  coagulates 
slowly  with  rennet,  giving  a  loose  spongy  curd  that  is  too  fragile  to  be  han- 
dled successfully;  and  second,  it  produces  a  curd  that  expels  whey  slowly. 
As  the  result  of  experiments  conducted  from  1905  to  1911,  Sammis  and 
Bruhn  have  brought  out  a  process  of  cheese  manufacture  wherein  the 
milk  is  pasteurized  by  the  flash  process  at  160  to  165°F.,  and  is  afterward 
acidified  with  hydrochloric  acid  which  restores  its  coagulability  with 
rennet  and  brings  the  acidity  to  a  point  where  the  whey  is  rapidly  expelled 
by  the  curd.  Several  factories  have  adopted  the  process;  the  Bowman 
Dairy  Co.  of  Chicago  has  equipped  two  of  its  milk  stations  with  outfits 
to  utilize  the  process,  and  during  the  flush  run  of  milk  in  the  summer  of 
1914,  used  it  in  making  335,000  Ib.  of  cheese.  Sammis  has  also  devised 
two  methods  of  making  cheese  from  the  buttermilk  of  pasteurized  cream. 

The  Work  of  Koplik. — In  this  country,  the  introduction  of  pasteuriza- 
tion to  the  city  milk  business  was  gradual.  Heated  milk  was  first  used 
by  a  few  pediatricians.  Then,  in  1889  the  first  milk  depot  was  opened  in 
New  York  City  under  the  direction  of  Dr.  Henry  Koplik.  This  insti- 
tution distributed  pasteurized  milk  and  through  its  operations  the  public 
began  to  understand  what  pasteurized  milk  was,  and  to  use  it.  The 
physicians  of  that  day  used  rather  higher  temperatures  in  pasteurizing 
than  are  recommended  now.  Dr.  Koplik  pasteurized  the  milk  he  dis- 
tributed at  185°  to  195°F.  because  he  found  that  milk  so  heated  kept 


266  CITY  MILK  SUPPLY 

well  in  a  moderately  cool  place  for  24  hr.,  whereas  the  milk  pasteurized 
at  from  150°  to  160°F.,  since  it  was  somewhat  carelessly  handled  by  the 
mothers,  soured  within  that  time. 

Work  of  Nathan  Straus. — Milk  charities  have  had  a.  powerful  influence 
in  spreading  the  gospel  of  pasteurization  and  in  this  connection  the  work 
of  Nathan  Straus  was  sound  and  far-reaching.  He  became  convinced 
that  the  infant  death  rate  could  be  materially  reduced  by  bettering  the 
milk  used  by  the  poor  and  he  believed  that  this  could  be  accomplished 
by  supplying  them  pasteurized  milk.  Accordingly  in  1893  in  New  York 
City  he  established  his  first  milk  depot.  From  the  beginning  and  ever 
afterward  the  work  was  carried  on  under  expert  medical  advice.  His 
first  infants'  milk  depot  was  open  from  June  to  November  and  distributed 
34,400  bottles  of  pasteurized  and  modified  milk.  The  success  attained 
was  so  great  that  Straus  was  encouraged  to  continue  the  experiment 
another  year  and  on  a  larger  scale;  so,  six  stations  were  maintained  in  1894, 
five  of  them  being  kept  open  from  the  middle  of  May  to  the  end  of  the 
heated  season  and  one  to  the  end  of  the  year  so  that  from  this  time  on 
the  service  was  continuous.  This  second  year,  306,446  bottles  were  dis- 
tributed which  was  a  ninefold  increase  from  the  previous  year.  There- 
after, the  demand  for  the  pasteurized  milk  grew  steadily  so  that  in  1906 
there  were  3,140,252  bottles  distributed  from  17  stations.  In  1894, 
Mr.  Straus  undertook  to  disabuse  the  public  of  the  idea  that  pasteurized 
milk  was  a  medicated  product,  by  selling  it  in  the  city  parks  at  1  ct. 
a  glass  and  for  this  purpose  milk  was  in  part  obtained  from  the  plant  of  the 
Appleberg  Hygienic  Dairy  Co.  of  Pauling,  N.  Y.  In  the  Straus  plant, 
milk  was  pasteurized  by  the  holder  process  for  20  min.  at  167°F.  The 
demand  often  taxed  the  facilities  of  the  plant  severely  but  from  the  very 
beginning  the  policy  was  adopted  of  distributing  no  milk  that  had  been 
pasteurized  for  more  than  24  hr.  The  Straus  Milk  Charities  were 
heartily  supported  by  the  New  York  City  Board  of  Health,  hospitals,  chari- 
table organizations  and  the  World,  which  encouragement  contributed  to 
their  success.  Following  the  introduction  of  this  pasteurized  milk  there 
was  a  marked  decline  in  the  infantile  mortality  rate  of  New  York  City, 
and  this  Mr.  Straus  and  others  believed  to  be  due  to  the  use  of  the  pas- 
teurized milk.  The  Board  of  Health  of  Brooklyn  found  the  infantile 
death  rate  of  that  city  very  high  and  in  1894  applied  to  Mr.  Straus  for 
help.  He  furnished  them  with  over  1,000  bottles  daily  and  there  followed 
a  reduction  in  the  deaths  of  children  that  was  comparable  with  that  in 
New  York  City. 

As  illustrative  of  the  good  results  that  followed  the  introduction  of 
pasteurized  milk,  the  experience  at  Randall's  Island  may  be  cited.  The 
waifs  picked  up  on  the  streets  of  New  York  were  taken  to  the  hospital  of 
this  institution  and  the  death  rate  among  them  was  very  high  although 
the  milk  was  obtained  from  a  carefully  selected  herd  pastured  on  the 


THE  MILK  CONTRACTOR 


267 


Island.  On  the  introduction  by  Mr.  Straus  of  a  pasteurizing  plant  at 
the  Institution  the  mortality  rate  dropped  decidedly,  although  there 
was  no  other  change  made  in  diet  or  hygiene.  The  reduction  in  the  death 
rate  of  children  on  the  Island  following  the  introduction  of  pasteurization 
is  shown  in  Table  80. 

TABLE  80. — CHILDREN'S  DEATH  RATE  AT  RANDALL'S  ISLAND,  N.  Y.,  PRIOR  TO  AND 
SUCCEEDING  THE  INTRODUCTION  OF  PASTEURIZATION 


Year                          Children  treated 

Number  of  deaths 

Percentage 

1895 

1,216 

511 

42.02 

1896 

1,212 

474 

39.11 

1897 

1,181 

524 

44.36 

Total 

3,609 

1,509 

41.81 

Pasteurization  begun  early  in  1898 

1898                          1,284 

255 

19.80 

1899 

1,097 

269 

24.52 

1900 

1,084 

300 

27.68 

1901 

1,028 

186 

18.09 

1902 

820 

181 

22.07 

1903 

542 

101 

18.63 

1904 

345 

57 

16.52 

Total  ..;V 

6,200 

1,349 

21.75 

Straus'  efforts  to  lower  the  infantile  death  rate  by  encouraging  the 
use  of  pasteurized  milk  attracted  the  attention  of  physicians,  sanitarians 
and  others  throughout  the  United  States,  especially  as  like  favorable  re- 
sults were  attained  in  Yonkers,  Philadelphia,  Pittsburgh,  and  Cincinnati, 
in  all  of  which  places  he  introduced  pasteurized  milk.  In  June,  1895, 
Straus  addressed  a  letter  to  the  Mayor  of  every  city  in  the  United  States 
urging  that  the  pasteurization  of  the  milk  of  the  poor  should  be  an  object 
of  municipal  solicitude  and  in  March,  1897,  a  letter  of  similar  tenor  but 
setting  forth  his  argument  in  more  detail  was  sent  to  all  Presidents  of 
Boards  of  Health  in  the  United  States  and  Canada.  Furthermore,  from 
the  inception  of  his  work  to  1912  he  addressed  scientific  societies  and  other 
bodies  both  in  America  and  Europe  in  advocacy  of  the  pasteurization 
of  milk  and  besides  wrote  magazine  articles  explaining  the  process  and 
urging  the  necessity  of  adopting  it. 

Pasteurization  Adopted  by  Milk  Contractors. — The  position  of  milk 
contractors  about  1895  was  becoming  very  difficult  for  the  sources  of  milk 
supply  had  been  pushed  further  and  further  away  from  the  city  so  that 
milk  was  shipped  from  a  considerable  distance  and  took  a  long  time  to 
reach  the  city;  much  of  the  milk  was  uniced  and  was  carelessly  handled  in 


268  CITY  MILK  SUPPLY 

transit.  The  inspection  of  dairies  was  not  common  so  that  a  large  part 
of  the  milk  was  unclean  to  start  with  and  much  of  that  which  was  not  so, 
was  likely  to  be  en  the  verge  of  souring  when  it  reached  the  city.  More- 
over the  large  contractors  were  confronted  with  the  problem  of  supplying 
summer  resorts  with  milk  shipped  from  their  city  plants.  Added  to  this 
was  the  menace  of  communicable  disease.  Previous  to  1881,  it  was  not 
generally  known  that  milk  could  carry  infection  but  thereafter  epidemics 
had  with  increasing  frequency  been  traced  to  milk  and  besides  it  was 
then  the  general  opinion  of  physicians  that  dirty  milk  was  a  potent 
cause  of  infant  morbidity.  It  was  apparent  that  the  system  of  milk 
supply  in  vogue  lent  itself  to,  rather  than  impeded,  the  spread  of  some 
kinds  of  sickness. 

Under  these  conditions  pasteurization,  whereby  the  milk  was  heated 
to  a  temperature  high  enough  to  kill  most  of  the  lactic  acid  bacteria  and 
all  of  the  disease  germs,  appealed  forcefully  to  the  city  milk  dealers.  It 
is  difficult  to  fix  the  date  at  which  the  commercial  pasteurization  of  milk 
was  actually  begun.  Apparently  it  was  first  used  in  New  York  State 
where  certain  manufacturers  of  condensed  milk  who  were  also  in  the  city 
milk  business,  found  that  the  keeping  powers  of  milk  were  enhanced  and 
no  detectable  flavor  was  imparted  to  it  by  heating  it  for  a  brief  period  to 
167°F.  which  temperature  was  later  reduced  to  140°F.  In  Baltimore  one 
dealer  pasteurized  milk  for  infants  as  early  as  1893,  but  it  was  not  till 
about  1904  that  any  part  of  the  general  supply  was  pasteurized.  Pas- 
teurizing was  begun  in  Cincinnati  in  1897,  in  New  York  in  1898,  in  Phila- 
delphia in  1899,  in  St.  Louis  in  1900,  in  Milwaukee  in  1903,  in  Boston  and 
in  Chicago  in  1908.  The  prime  object  was  to  prolong  the  power  of  milk 
to  keep.  Within  limits  this  is  perfectly  legitimate  and  commendable. 
We  do  not  hesitate  to  keep  eggs,  butter,  cheese  and  a  host  of  other  things 
by  putting  them  in  cold  storage,  nor  to  preserve  fruits  and  vegetables  by 
canning  them.  In  fact  it  would  be  a  senseless  waste  not  to  thus  conserve 
our  food  supply.  This  is  as  true  of  milk  as  of  any  other  food  and  can  only 
be  rationally  objected  to  on  two  grounds,  namely:  first,  that  the  milk  is 
held  so  long  that  either  its  food  value  becomes  impaired  or  that  while 
apparently  usable  it  has  in  fact  become  injurious;  and  second,  that  the 
process  is  used  to  defraud  the  consumer  by  making  it  possible  to  sell  him 
milk  so  inferior  that  if  the  normal  course  of  decomposition  was  not  inter- 
fered with,  the  milk  would  reach  him  in  such  a  state  that  he  would  not 
buy  it. 

The  contractors  generally  adopted  the  flash  process  of  pasteurization. 
At  first  high  temperatures  were  used  but  it  was  found  that  the  milk  ac- 
quired a  cooked  taste.  The  exact  temperature  at  which  this  flavor  becomes 
perceptible  to  the  consumer  varies  with  the  degree  of  heat  employed,  the 
time  exposure  and  the  acuteness  of  taste  of  the  consumer  but  for  most 
people  is  at  about  158°F.  It  was  also  found  that  a  minute's  exposure  at 


THE  MILK  CONTRACTOR  269 

155°F.,  and  even  less  at  higher  temperatures  adversely  affects  the  cream 
line.  So,  despite  the  fact  that  in  pasteurizing  milk  by  this  process,  a  tem- 
perature of  176°F.  must  be  used  to  kill  all  disease  germs,  because  the  cir- 
culating milk  is  not  heated  equally  since  that  in  contact  with  the  heating 
surfaces  of  the  machines  moves  more  slowly  than  the  rest,  in  practice, 
much  lower  temperatures  were  employed.  The  pasteurizers  were  built 
so  that  the  speed  at  which  the  milk  passed  through  them  could  be  con- 
trolled by  the  operator  and  pasteurizing  was  actually  done  at  tempera- 
tures ranging  between  140°  and  165°F.  Indeed,  the  tendency  was  toward 
even  lower  temperatures;  Dr.  Evans  stated  in  1910  that  prior  to  the 
enactment  of  the  latest  law  governing  pasteurizing  the  average  maximum 
of  pasteurization  in  the  city  of  Chicago  was  128°F.  Pasteurization  of 
this  sort  at  these  temperatures  did  not  protect  the  public  from  disease, 
and  it  is  manifest  that  dealers  were  not  greatly  concerned  in  this  phase  of 
the  subject  but  were  employing  pasteurization  solely  to  delay  the  souring 
of  their  milk.  It  did  this  so  effectively,  that  without  cooling,  it  would 
keep  sweet  till  delivered  to  customers,  hence  not  a  few  dealers  regarded 
pasteurizing  as  a  means  of  cutting  down  ice  bills. 

Moreover  pasteurization  was  misused  in  another  way  by  contractors, 
in  that  milk  sometimes  received  two  or  more  pasteurizations  before  it 
reached  the  consumers.  It  was  pasteurized  at  plants  in  the  country  and 
was  repasteurized  on  its  arrival  in  the  city  and  some  dealers  gave  part  of 
the  milk  another  pasteurization,  for  that  which  came  back  undelivered  on 
the  wagons  was  heated  again  and  sent  out  to  customers. 

A  further  abuse  was,  that  in  some  plants,  particularly  those  in  the 
smaller  cities,  little  attention  was  paid  to  the  care  of  the  pasteurizing 
machines,  so  that  they  became  very  dirty  and  the  milk  ill-flavored  and  of 
poor  keeping  quality. 

Finally,  pasteurization  was  used  covertly;  one  large  firm  in  New  York 
City  used  the  flash  process  for  5  years  before  it  was  compelled  to  announce 
to  its  customers  that  it  was  selling  pasteurized  milk.  In  1906,  the  New 
York  City  Board  of  Health  forbade  clandestine  pasteurization  and  in  the 
spring  of  1910  had  a  law  passed  fixing  the  time  and  temperatures  at  which 
milk  must  be  pasteurized.  Laws  of  the  same  sort  were  soon  passed  by 
other  cities.  The  temperature  scales  decreed  by  New  York  and  Chicago 
are  given  in  Tables  81  and  82. 

While  this  commercial  development  of  the  flash  process  was  going  on 
the  holder  process  was  attracting  the  attention  of  scientific  investigators 
and  its  use  at  different  temperatures  and  for  various  time  periods  began 
to  be  advocated  by  them.  Even  after  its  superior  merits  were  demon- 
strated and  laws  tending  to  bring  about  its  adoption  were  passed  it  was 
regarded  with  disfavor  by  contractors  in  general  and  they  moved  with 
extreme  slowness  in  altering  their  plants  for  its  installation.  Its  first 
cost  was  greater  than  that  of  the  flash  process  and  where  the  latter  was 


270  CITY  MILK  SUPPLY 

TABLE  81. — NEW  YORK  CITY  SCALE  OF  TEMPERATURES  FOR  PASTEURIZING 
Not  less  than 

158°F.  for  at  least 3  min. 

155°F.  for  at  least 5  min. 

152°F.  for  at  least 10  min. 

148°F.  for  at  least 15  min. 

145°F.  for  at  least 18  min. 

140°F.  for  at  least . ».: , 20  min. 

1  At  the  present  time  no  milk  is  considered  pasteurized  within  the  meaning  of  the 
New  York  City  law  unless  it  has  been  heated  to  from  142°  to  145°F.  for  not  less  than  30 
min. 

TABLE  82. — CHICAGO  SCALE  OF  TEMPERATURES  FOR  PASTEURIZING  MILK 
A  uniform  heating  of 

165°F.  maintained  for  1  min. 
160°F.  maintained  for  1%  min. 
155°F.  maintained  for  5  min. 
158°F.  maintained  for  15  min. 
HOT.  maintained  for  20  min. 

already  in  operation  the  substitution  of  the  former  necessitated  consider- 
able expenditure  and  the  longer  time  required  to  pasteurize  the  milk  was 
a  further  objection  to  it  in  the  eyes  of  the  dealer.  So  it  began  to  be  felt 
that  the  contractors  were  opposing  a  necessary  reform. 

For  all  of  these  reasons  the  practice  of  pasteurization  on  a  commercial 
scale  fell  into  disrepute  with  the  public.  Much  blame  therefor  may  with 
justice  be  placed  on  the  contractors  but  it  should  be  remembered  that  it 
was  a  period  of  experimentation  and  that  these  men  had  the  faith  to  put 
large  sums  of  money  in  the  process  at  a  time  when  scientific  and  popular 
opinion  was  very  sceptical  as  to  the  value  and  even  the  possibility  of 
efficiently  pasteurizing  any  large  part  of  the  milk  supply.  In  all  probabil- 
ity the  fact  that  milk  dealers  persisted  in  espousing  pasteurization,  forced 
scientific  investigation  of  its  merits  and  in  a  sense  compelled  the  develop- 
ment of  a  process  that  could  be  officially  sanctioned. 

Arguments  For  and  Against  Pasteurization. — At  this  point  it  is  well 
to  consider  the  arguments  that  are  advanced  for  and  against  pasteuriza- 
tion ;  they  have  been  widely  discussed  and  have  been  met  with  experiments 
that  were  designed  to  support  or  disprove  them. 

At  the  start  it  may  be  noted  that  the  mere  fact  that  milk  has  been 
pasteurized  does  not  make  it  better  than  raw  milk;  no  new  quality  is 
imparted  to  the  milk  and  there  is  no  harmful  quality  in  the  milk  itself 
to  be  removed.  There  are  however  five  excellent  reasons  for  pasteurizing 
milk. 

Pasteurization  Prevents  the  Spread  of  Contagion  by  Infected  Milk.— 
The  first  and  most  important  of  them  all  is  that  it  saves  the  lives  of  men 
and  of  animals.  To  protect  the  former  appeals  to  us  principally  from  the 
selfish  and  humanitarian  viewpoints  but  it  also  has  its  economic  aspect. 


THE  MILK  CONTRACTOR  271 

We  do  not  want  to  contract  typhoid,  diphtheria,  septic  sore  throat  or  other 
epidemic  diseases  ourselves  through  the  use  of  milk,  nor  do  we  want  others 
to.  The  cost  of  controlling  outbreaks  of  epidemic  disease,  and  the 
financial  loss  resulting  from  the  destruction  of  human  life  and  to  business 
when  such  epidemics  do  occur,  dispose  the  tax  payers  to  regard  with  favor 
the  use  of  such  a  simple  means  as  pasteurization,  to  minimize  the  dangers 
from  communicable  diseases. 

Likewise,  the  stock  owner  is  slowly  learning  that  he  cannot  afford  to 
take  the  risk  of  bringing  back  to  his  farm  from  the  creamery  and  cheese 
factory  skim-milk  and  whey  that  are  likely  to  contain  the  germs  of 
tuberculosis  and  contagious  abortion  or  possibly  the  virus  of  foot-and- 
mouth  disease  or  that  may  even  be  infected  with  germs  of  human  disease 
which  may  bring  some  member  of  his  family  low. 

Pasteurization  Lowers  the  Infantile  Morbidity  Rate. — Second,  pas- 
teurization by  reducing  the  number  of  germs  in  milk  lowers  the  infantile 
morbidity  and  mortality  rates.  It  seems  to  be  true  that  the  intestines 
of  small  children  are  tender  and  unable  to  cope  with  large  numbers  of 
bacteria  so  that,  as  a  result  of  drinking  milk  of  high  bacterial  content, 
babies  are  prone,  especially  in  hot  weather,  to  develop  diarrheal  disorders 
that  are  often  fatal. 

Pasteurization  Checks  Bacterial  Changes  in  Milk. — Third,  pasteuriza- 
tion checks  bacterial  changes  in  milk  that  may  result  in  the  formation  of 
toxins  and  other  products  of  bacterial  decomposition  that  have  not  been 
isolated  but  which  nevertheless  are  believed  to  exist  and  to  be  harmful. 

Pasteurization  Delays  the  Souring  of  Milk. — Fourth,  by  partially 
destroying  the  lactic  acid  bacteria  and  other  germs  the  keeping  quality 
of  milk  is  improved — a  result  desired  by  both  the  vender  and  purchaser 
of  milk. 

Uninspected  Milk  Should  be  Pasteurized. — Fifth,  under  present  condi- 
tions much  uninspected  and  even  dirty  milk  is  bound  to  be  sold,  and  it 
is  better  that  the  public  be  afforded  the  protection  that  pasteurization 
gives  than  that  it  hazard  all  the  dangers  that  such  raw  milk  may  conceal. 

Heating  Milk  Unnatural. — The  objections  that  have  been  made  to 
pasteurization  are  many;  some  of  them  were  so  grave  as  to  raise  serious 
doubts  as  to  whether  the  process  could  be  unreservedly  commended  while 
others,  though  they  perhaps  caused  some  hesitation  about  accepting  it, 
were  not  so  important.  In  the  first  place,  it  was  obvious  that  the  heating 
of  milk  was  not  nature's  way;  young  animals  took  milk  without  its  being 
heated,  therefore  some  questioned  why  man  should  not.  In  reality  the 
comparison  is  not  a  true  one  for  the  young  calf  applies  its  mouth  to  the  teat 
and  so  gets  its  milk  directly  from  the  udder  without  contamination  from 
external  sources,  whereas  the  milk  that  man  gets,  is  drawn  into  an  open 
vessel  and  is  usually  contaminated  over  and  over  again  before  it  is  used. 
So  man  getting  the  milk  under  unnatural  conditions  is  justified  in  taking 


272  CITY  MILK  SUPPLY 

artificial  means  to  make  its  acquired  impurities  harmless. .  As  man  heats 
other  foods,  it  is  natural  that  he  should  milk.  Rosenau  has  pointed  out 
that  milk  is  the  only  nitrogenous  food  that  man  eats  raw.  In  fact,  in 
many  countries  it  is  customary  to  cook  milk  but  in  the  United  States 
it  was  not,  so  that  this  new  product,  heated  milk,  was  viewed  with 
suspicion  and  had  to  make  its  way  slowly. 

Pasteurizing  Milk  and  Dirty  Dairying. — Another  objection  that  was 
raised  to  pasteurization  was  that  it  would  militate  against  sanitary  dairy- 
ing. It  was  known  that  much  of  the  milk  came  into  the  cities  from  very 
dirty  dairies  and  it  was  felt  that  pasteurization  would  tend  to  perpetuate 
their  existence  by  making  the  milk  from  them  more  readily  marketable, 
for  in  the  raw  state  it  might  be  expected  to  spoil  quickly  on  account  of 
the  heavy  contamination  that  it  had  received,  whereas  by  pasteurization 
this  might  be  delayed  till  the  contractor  could  place  it  in  the  home  of  the 
consumer.  It  was  felt,  too,  that  pasteurization  would  encourage  the  use 
of  unclean  methods  by  the  producer  for,  knowing  that  the  milk  was  to 
be  pasteurized,  he  would  feel  that  the  effects  of  his  carelessness  would 
be  obliterated. 

Spore-bearing  Organisms  Survive  Pasteurization. — The  experiments 
of  Fltigge  in  1894  greatly  influenced  many  adversely  toward  pasteurized 
milk.  He  heated  milk  to  near  the  boiling  point  till  few  if  any  other 
bacteria  than  spore  formers  survived  and  then  by  employing  suitable 
methods  isolated  12  cultures  of  bacteria  that  when  grown  in  milk  at 
98°F.  for  2  days,  peptonized  it.  Of  these  12  cultures,  three  when  so 
grown  in  milk,  proved  poisonous  when  fed  to  dogs;  the  others  did  not. 
From  this  work,  which  nowadays  would  not  be  considered  extensive 
enough  to  be  conclusive,  the  inference  was  widely  drawn  that  noxious 
spore-forming  bacteria  survived  pasteurization  and  it  was  believed  that 
they  were  particularly  dangerous  in  that  they  rotted  the  milk  without 
making  its  putrid  condition  apparent  to  the  consumer.  In  criticism  of 
Fliigge's  results  it  has  been  said  that  he  grew  the  organisms  at  tempera- 
tures which  assured  a  maximum  of  toxin  production  and  that  according 
to  his  own  account  his  cultures  were  in  a  stinking  condition  when  fed  to 
the  dogs.  Careful  experimentation  has  demonstrated  that  at  the  tem- 
peratures now  employed  in  this  country  in  pasteurization,  enough  lactic 
acid  bacteria  survive  to  overgrow  any  peptonizing  forms  that  may  be 
present  and  so  to  prevent  putrefaction  taking  place. 

In  an  investigation  covering  18  months  extending  from  the  spring  of 
1913  to  the  fall  of  1914,  Ford  and  Pryor  studied  the  market  milk  of  Balti- 
more and  Washington  in  an  attempt  to  repeat  Fliigge's  experiments. 
Fliigge  held  that  milk  heated  to  various  temperatures  shows  after  incu- 
bation, at  71.6°F.  or  at  98.6°F.-  two  sorts  of  decomposition  the  one  being 
explosive  and  due  to  gas-producing  anaerobes  and  the  other  consisting 
of  a  slow  liquefaction  of  the  proteins  of  the  milk,  due  to  peptonizing 


THE  MILK  CONTRACTOR  273 

aerobes.  The  latter  group  of  organisms  seemed  to  him  particularly  sig- 
nificant, for  the  changes  produced  took  place  slowly  and  even  though  the 
milk  teemed  with  microbes,  its  abnormal  condition  might  be  overlooked. 
The  growth  of  the  spore  bearers  would  ordinarily  be  restrained  by  the 
lactic  acid  bacteria ;  so  only  in  milk  heated  enough  to  destroy  these  lactic 
organisms,  would  the  spore  bearers  develop  sufficiently  to  either  change 
the  character  of  the  milk  or  to  endanger  the  health  of  children  who  might 
drink  it.  Fliigge  believed  that  the  spores  of  the  peptonizing  bacteria 
would  resist  the  action  of  the  gastric  juice  and  finding  proper  conditions 
for  development  in  the  lower  bowel  would  multiply  there  and  give  rise 
to  the  grave  symptoms  of  intoxication  seen  in  summer  complaint.  The 
several  organisms  isolated  from  heated  milk  by  Fliigge  were  later  studied 
by  Gotschlich  and  Kaensche  who  found  the  principal  anaerobe  to  be  the 
B.  butyricus  of  Hueppe  and  the  principal  aerobes,  B.  subtilis,  B.  mesen- 
tericus  vulgatus  and  B.  mesentericus  fusus. 

Ford  and  Pryor  examined  milk  of  21  dairies  in  Baltimore  which  repre- 
sented nearly  every  sort  of  milk  sold  in  the  city  and  Ford  continuing  the 
studies  examined  24  specimens  of  raw  milk  from  17  different  dairies  and 
27  specimens  from  eight  sources  of  the  commercially  pasteurized  milk  of 
Washington.  The  results  in  the  two  cities  were  essentially  the  same. 
The  investigators  heated  the  milk  to  different  temperatures,  viz.,  140°, 
149°,  176°,  185°,  212°F.  and  under  20  Ib.  pressure  for  from  5  to  35  min. 
according  to  the  experiment,  and  incubated  the  heated  or  pasteurized 
milk  both  aerobically  and  anaerobically  at  71.6°  and  98.6°F.  for  48  to  96 
hr.  The  condition  of  the  incubated  sample  was  recorded  and  agar  plates 
poured  from  it.  The  presence  of  B.  welchii  was  tested  for  by  injecting 
the  incubated  sample  into  the  ear  vein  of  a  rabbit.  The  conclusions 
arrived  at  were: 

1.  As  first  pointed  out  by  Fliigge,  milk  always  contains  heat  resistant 
spores  of  aerobic  and  anaerobic  bacteria  which  by  their  development  can 
give  rise  to  disagreeable  and  unwholesome  changes  in  milk,  converting 
it  from  a  food  of  great  nutritive  value  into  an  undesirable,  if  not  a  danger- 
ous, article  of  diet. 

2.  These  changes  take  place  in  milk  heated  to  any  temperature  from 
149°  to  212°F.  and  kept  at  any  temperature  from  71.6°  to  98.6°F.,  but 
not  at  that  of  the  ice  box  at  39.2°  to  42.8°F. 

3.  Spores  of  these  bacteria  survive  for  a  long  time  in  milk  kept  on 
ice  and  when  such  milk  is  transferred  to  higher  temperatures  they  can 
initiate  their  characteristic  changes  in  it. 

4.  The  problem  of  pasteurization  must  be  worked  out  on  the  basis 
of  changes  that  occur  in  milk  heated  140°  to  149°F. 

5.  The  most   important   anaerobic   species  is   B.   welchii  which   is 
believed  to  be  universally  present.     Aerobic  spore-bearing  bacteria  are 
also  found  in  practically  all  samples  and  belong  in  general  to  the  group 

IS 


274  CITY  MILK  SUPPLY 

of  gelatin  liquefiers.  Such  species  do  not  develop  in  raw  milk  nor  in 
Washington  pasteurized  milk — pasteurized  at  140  to  149°F.  for  30  to  35 
min. — only  the  ordinary  lactic  acid  bacteria  being  found. 

6.  How  far  these  spore-bearing  organisms  play  a  role  in  the  clinical 
condition,  especially  that  of  children,  is  yet  to  be  proved. 

In  continuation  of  the  Baltimore  work  Lawrence  and  Ford  from  1913 
to  1916  worked  out  the  cultural  reactions  of  250  spore-bearing  bacteria 
isolated  from  68  samples  of  milk,  12  of  raw  milk,  12  of  milk  pasteurized 
at  140°F.,  32  of  milk  heated  to  185°F.  and  12  of  boiled  milk.  They 
believe  the  cultures  give  an  accurate  idea  of  the  spore-bearing  bacteria 
of  the  milk  of  Baltimore  and  probably  of  that  elsewhere.  By  their  com- 
bined development  in  heated  milk,  these  organisms  give  rise  to  the  putrid 
decomposition  so  often  observed;  in  the  majority  of  instances  they  are 
energetic  protein-splitters  and  in  practically  every  case  dissolve  the  pro- 
tein in  milk,  either  before  or  after  a  preliminary  coagulation. 

After  establishing  the  various  types  of  organisms  by  the  study  of 
250  cultures  from  the  68  samples,  another  series  of  milks,  also  subjected 
to  various  treatments,  was  investigated  with  the  object  of  testing  the 
preliminary  classification  adopted.  The  types  were  abundantly  con- 
firmed but  no  new  organisms  were  isolated  which  indicates  that  the  or- 
ganisms represent  the  spore  bearers  usually  present  in  Baltimore  milk. 
In  the  original  250  cultures  the  various  species  were  found  in  the  following 
proportions : 

B.  cereus — FranklancL 124 

B.  subtilis  (Ehrenberg)— Cohn 79 

B.  albolactus — Migula 25 

B.  vulgatus  (Fliigge) — Trevisan 15 

(B.  mesentericus  vulgatus — Fliigge) 

B.  mesentericus  (Fliigge) — Migula 2 

(B.  mesentericus  fuscus — (Fliigge) 

B.  fusifomis— Gottheil 2 

B.  petasites — Gottheil 1 

B.  cohaerens — Gottheil 1 

B.  terminalis — Migula •  •  •  •  1 

Besides,  the  following  spore-bearing  species  were  isolated  from  other 
sources  which,  partly  from  the  work  of  others  and  partly  because  they 
are  not  infrequent  in  milk  products,  the  authors  believe  may  occur  in  milk: 

B.  mycoides — Fliigge. 

B.  megatherium — De  Barry. 

B.  simplex — Gottheil. 

B.  aterrimus — Lehman  and  Newmann  (B.  mesentericus  niger — Lunt). 

B.  niger — Migula  (B.  lactis  niger  Gorini). 

B.  globigii — Migula  (B.  mesentericus  ruber — Globig). 

Shippen  investigated  the  growth  of  B.  welchii  in  milk.  He  found 
that  when  it  is  transferred  to  that  medium  with  the  common  aerobic 


THE  MILK  CONTRACTOR  275 

spore  bearers  or  with  B.  troilii  it  assumes  the  power  of  growth  under 
aerobic  conditions  and  its  reactions  overwhelm  those  of  the  bacteria 
with  which  it  grows.  When  the  organisms  are  heated  to  140°F.  St. 
lacticus  inhibits  the  reactions  produced  by  B.  welchii  upon  milk  in 
the  presence  of  B.  troilii  and  the  aerobic  spore  bearers,  unless  these 
spore  bearers  are  present  in  vast  numbers,  when  it  fails  to  do  so,  as  it  does 
when  no  heat  is  applied.  The  reactions  observed  in  milk  heated  at 
temperatures  ranging  from  140°  to  185°F.  may  be  simulated  in  the  pres- 
ence of  B.  welchii  by  the  growth  of  the  aerobes  commonly  surviving 
the  temperatures  considered  after  the  application  of  the  desired  degree 
of  heat. 

H.  R.  Brown  made  a  study  of  the  anaerobic  bacteria  in  the  market 
milk  of  Boston,  and  the  results  of  his  studies  appear  in  the  reports  of  the 
Massachusetts  State  Board  of  Health. 

Since  Fliigge's  time  painstaking  investigations  have  been  made  to  de- 
termine the  bacteria  that  survive  pasteurization.  Inquiry  has  been 
focussed  on  the  lactic  bacteria,  the  coli,  the  streptococci  and  the  spore 
formers. 

Other  Bacteria  that  Survive  Pasteurization. — Ayres  and  Johnson 
working  under  laboratory  conditions  that  precluded  recontamination  of 
the  milk,  studied  the  bacteria  that  survive  pasteurization  by  the  holder 
process  at  several  temperatures.  They  classify  the  bacteria  in  raw  milk 
in  four  groups,  namely:  (1)  the  acid;  (2)  the  inert;  (3)  the  alkali;  and  (4) 
the  peptonizing  groups.  The  acid  group  is  divided  into  two  subgroups, 
to  wit:  (a)  the  acid-coagulating,  which  coagulates  milk  in  less  than  14 
days;  and  (6)  the  acid  group  which  produces  acid  but  does  not  coagulate 
milk  in  14  days.  In  raw  milk  the  inert  group  is  the  largest.  In  milk 
pasteurized  30  min.  at  145°F.  there  is  plainly  a  great  increase  in  the  pro- 
portion of  the  acid  and  acid-coagulating  subgroups  while  the  alkali  and 
peptonizing  groups  form  smaller  percentages  of  the  whole.  At  160°F. 
the  acid  group  is  still  the  largest  but  the  acid-coagulating  subgroup  is 
composed  of  bacteria  that  coagulate  very  slowly.  At  this  temperature 
the  alkali  group  is  greatly  reduced  and  the  peptonizing  group  is  reduced 
to  the  minimum.  At  170°F.,  the  acid  group  remains  about  the  same,  but 
the  organisms  produce  acid  and  coagulation  very  slowly.  The  alkali 
group  is  practically  destroyed,  though  an  occasional  sample  may  show 
this  group  in  fairly  high  percentage.  The  most  important  change  at  this 
temperature  is  in  the  peptonizing  group  which,  relative  to  the  total 
bacteria,  begins  to  show  a  percentage  increase.  At  180°F.,  this  increase 
of  the  peptonizing  group  is  very  striking  for  no  less  than  75  per  cent,  of 
the  surviving  bacteria  are  peptonizers.  At  this  temperature  none  of  the 
acid-coagulating  subgroup  and  only  a  small  percentage  of  the  acid  sub- 
group are  found.  At  190°F.  and  200°F.,  the  bacterial  groups  survive  in 
about  the  same  relative  proportion  as  they  do  at  180°F.  From  these 


276  CITY  MILK  SUPPLY 

experiments  it  is  manifest  that  170°F.  is  a  critical  temperature  in  pas- 
teurizing, for  in  milk  pasteurized  above  this  temperature  there  is  a  tend- 
ency for  the  peptonizing  bacteria  to  predominate.  Ayres  concludes 
that  when  the  bacterial  flora  of  pasteurized  milk  is  under  discussion  the 
temperature  of  the  process  is  of  fundamental  importance  and  he  cautions 
that  these  summaries  represent  average  conditions  and  are  subject  to 
exceptions. 

Ability  of  B.  coli  to  Survive  Pasteurization. — Certain  boards  of  health 
have  taken  the  presence  of  more  than  a  few  colon  bacteria  in  pasteurized 
milk  as  evidence  that  the  pasteurization  has  not  been  efficient  or  that 
subsequent  thereto  the  milk  has  been  contaminated.  The  attempt  to 
establish  this  criterion  for  pasteurized  milk  evoked  a  storm  of  protest  and 
led  to  investigations  of  the  ability  of  B.  coli  to  survive  pasteurization. 
Ayres  and  Johnson  conducted  a  series  of  experiments  to  determine  the 
question  and  reached  the  following  conclusions: 

"  1.  The  thermal  death  point  of  174  cultures  of  colon  bacilli  isolated  from  cow 
feces,  milk  and  cream,  human  feces,  flies  and  cheese,  showed  considerable  varia- 
tion when  the  cultures  were  heated  in  milk  for  30  min.  under  pasteurizing  con- 
ditions. 

"At  140°F.,  the  lowest  pasteurizing  temperature,  95  cultures,  or  54.59  per 
cent.,  survived;  at  145°F.,  the  usual  pasteurizing  temperature  12,  or  6.89  per  cent., 
survived. 

"One  culture  was  not  destroyed  at  150°F.  on  the  first  heating,  but  thereafter, 
in  repeated  experiments,  always  was. 

"2.  There  is  a  marked  difference  in  the  effect  of  heating  at  140°F.  Although 
there  is  a  difference  of  but  5°,  87.3  per  cent,  of  the  cultures  which  survived  at 
140°F.  were  destroyed  at  145°F. 

"3.  Considerable  variation  was  found  in  the  thermal  death  point  of  the  colon 
bacilli  that  survived  145°F.  When  the  12  cultures  that  survived  were  heated 
again  at  the  same  temperature,  many  did  not  survive  and  different  results  were 
obtained  at  each  repeated  heating. 

"145°F.  for  20  min.  seems  a  critical  temperature  for  colon  bacilli. 

"4.  All  of  the  174  cultures  studied  had  a  low  majority  thermal  death  point 
but  were  able  to  survive  pasteurizing  temperatures  on  account  of  the  survival 
of  a  few  cells. 

"5.  The  colon  test  as  an  index  of  the  efficiency  of  pasteurization  is  compli- 
cated by  the  ability  of  certain  strains  to  survive  a  temperature  of  145°F.  for  30 
min.  and  to  develop  rapidly  when  the  pasteurized  milk  is  held  under  temperature 
conditions  that  might  be  met  during  storage  and  delivery. 

"The  presence  of  a  large  number  of  colon  bacilli  immediately  after  the  heat- 
ing process  may  indicate  improper  treatment  of  the  milk. 

"6.  If  milk  is  pasteurized  at  150°F.  or  above  for  30  min.,  the  results  indicate 
that  no  colon  bacilli  would  survive.  Under  such  conditions  the  colon  test  may 
be  of  value  in  determining  the  efficiency  of  pasteurization.  However,  further 
research  may  discover  strains  of  colon  bacilli  that  will  survive  this  temperature 
and  even  higher  ones." 


THE  MILK  CONTRACTOR  277 

Ability  of  the  Streptococci  to  Survive  Pasteurization. — Because  the 
Smith  Streptococcus  often  is  conveyed  from  man  to  the  udder  of  the 
cow  and  causes  milk-borne  outbreaks  of  septic  sore  throat  and  because 
garget,  a  common  affection  of  the  cow's  udder,  is  often  caused  by  strepto- 
cocci, the  ability  of  streptococci  to  withstand  pasteurization  excited  inter- 
est. The  question  was  investigated  by  Ayres  and  Johnson.  They  found 
that  the  thermal  death  point  of  139  cultures  of  streptococci  isolated  from 
cow's  feces,  from  the  udder,  from  the  mouth  of  the  cow  and  from  milk  and 
cream  showed  a  wide  variation  when  the  organisms  were  treated  for  30 
min.  under  pasteurizing  conditions. 

At  140°F.,  the  lowest  pasteurizing  temperature,  89  cultures,  or  64.03 
per  cent.,  survived;  at  145°F.,  the  usual  pasteurizing  temperature,  46 
cultures,  or  33.07  per  cent. ;  at  160°F.,  2.58  per  cent. ;  and  at  165°F.  all  were 
killed. 

On  the  whole,  streptococci  from  the  udder  were  less  resistant  and  those 
from  the  milk  and  cream  were  more  so  than  those  from  the  mouth  of  the 
cow  and  from  cow's  feces. 

At  140°F.  all  of  the  18  cultures  from  the  milk  and  cream  survived;  at 
145°F.  17,  or  94.94  per  cent.,  and  at  155°F.,  nine  cultures,  or  50  per  cent., 
withstood  the  heating;  all  of  the  cultures  died  on  exposure  to  165°F.  for 
20  min. 

Among  the  139  cultures  of  streptococci  there  were  22  that  formed  long 
chains  and  that  were  considered  typical  streptococci;  the  rest  were  held 
to  be  atypical.  Of  the  typical  streptococci  12,  or  54.54  per  cent.,  survived 
heating  at  135°F.  for  30  min.,  9,  or  40.91  per  cent.,  survived  at  140°F., 
and  a  single  culture,  or  4.54  per  cent.,  withstood  heating  at  145°F.  At 
150°F.  for  30  min.  all  of  the  typical  streptococci  were  destroyed.' 

The  117  atypical  streptococci  were  more  resistant.  At  140°F., 
68.37  per  cent,  survived;  at  145°F.,  38.46  per  cent.;  at  160°F.,  2.56  per 
cent. ;  while  at  165°F.  all  were  destroyed. 

The  authors  conclude  that  two  classes  of  streptococci  survive  pas- 
teurization, viz. :  (1)  Streptococci  that  have  a  low  majority  thermal  death 
point  but  among  which  a  few  cells  are  able  to  survive  the  pasteurizing 
temperature.  This  ability  of  a  few  streptococci  to  survive  the  pasteur- 
izing temperature  may  be  due  either  to  certain  resisting  characteristics 
peculiar  to  a  few  cells  or  to  some  protective  influence  of  the  milk.  (2) 
Streptococci  having  a  high  majority  thermal  death  point.  These  survive 
because  the  majority  thermal  death  point  is  above  the  pasteurizing  tem- 
perature. This  ability  to  withstand  heating  is  a  permanent  character- 
istic of  certain  strains  of  streptococci.  These  experiments  are  comparable 
to  commercial  pasteurization  by  the  holder  process  but  had  more  cultures 
been  examined  other  results  possibly  might  have  been  obtained. 

Effect  of  Pasteurization  on  Mould  Spores. — The  effect  of  pasteuriza- 
tion on  mould  spores  has  recently  been  studied  by  Thorn  and  Ayres.  The 


278  CITY  MILK  SUPPLY 

spores  of  moulds  are  certainly  present  and  are  often  abundant  in  market 
milk.  Studies  were  made  with  pure  cultures  of  a  series  of  moulds  including 
several  species  of  Aspergillus  and  of  the  mucors  with  the  addition  in  some 
experiments  of  Oidium  (oospora)  lactis  and  one  strain  of  Fusarium.  Ex- 
periments were  made  to  test  the  effect  of  temperature  in  the  holder,  and  in 
the  flash  processes  of  pasteurization,  and  by  dry  heat.  The  results  agree 
in  general  with  the  bacteriological  studies  of  pasteurization. 

Very  few  of  the  spores  survived  heating  in  milk  to  145°F.  for  30  min. 
Certain  moulds,  notably  Aspergillus  fumigatus  and  A.  flavus,  do  survive 
but  they  occur  only  rarely  in  milk.  Oidium  lactis  and  the  mucors  which 
are  probably  more  important  as  milk-borne  organisms  than  all  the  other 
moulds,  are  destroyed  at  this  temperature  and  exposure.  So  pasteuriza- 
tion of  milk  at  145°F.  may  be  regarded  as  destroying  mould  spores  com- 
pletely enough  to  render  them  a  negligible  quantity. 

In  using  the  flash  process  of  pasteurization  temperatures  of  165°F.  to 
175°F.  for  30  sec.  are  commonly  employed.  It  was  found  that  very  few  of 
the  moulds  were  killed  at  145°F.  for  30  sec.  but  that  nearly  all  were  in  that 
time  at  155°F.  and  likewise  that  30  sec.  exposure  at  165°F.  to  175°F. 
destroys  practically  all  spores  as  they  are  found  in  milk,  although  a  few 
conidia  in  some  species  may  occasionally  survive.  The  observation 
that  the  moulds  were  killed  at  temperatures  of  from  165°F.  to  175°F.  is 
confirmed  by  the  results  of  Webster  of  the  Bureau  of  Chemistry  showing 
that  commercial  butter  made  from  flash-pasteurized  cream  contained  no 
mould  spores  whereas  cultures  from  commercial  butter  contained  20,000 
to  60,000  per  cubic  centimeter. 

Multiplication  of  Bacteria  in  Pasteurized  Milk. — Certain  investigators 
were  of  the  opinion  that  bacteria  increased  more  rapidly  in  pasteurized 
than  in  raw  milk  and  that  this  constituted  a  serious  objection  to  its  use, 
for  in  cooling,  bottling  and  in  the  subsequent  handling  of  it,  the  milk  was 
often  rather  heavily  contaminated,  but  careful  work  by  Ayres  and  Johnson 
showed  this  criticism  to  be  ill-founded  for  when  the  bacterial  increment 
in  an  efficiently  pasteurized  milk  is  compared  with  that  in  a  clean  raw 
milk  held  at  the  same  temperature,  the  two  are  found  to  be  about  the 
same. 

Destruction  of  Toxins  by  Pasteurization. — Others  pointed  out  that 
pasteurization  probably  does  not  destroy  toxins  that  may  develop  as  the 
result  of  bacterial  growth  in  milk.  If  such  toxins  exist  they  have  not 
been  isolated,  therefore  the  temperatures  at  which  they  are  destroyed 
are  unknown.  The  true  bacterial  toxins  are  not  destroyed  by  pasteuri- 
zation by  heating  at  140°F.  for  20  min.  but  heating  milk  to  this  temper- 
ature kills  many  germs  and  so  makes  the  further  formation  of  toxins  in 
it  less  probable.  Of  course,  raw  milk  that  supports  a  heavy  growth  of 
germs  may  contain  toxins  and  would  be  quite  as  injurious  before 
pasteurization  as  afterward. 


THE  MILK  CONTRACTOR 


279 


Physical  and  Chemical  Changes  Induced  in  Milk  by  Pasteurizing. — 

It  is  charged  that  pasteurizing  milk  changes  its  physical  and  chemical 
properties  to  its  detriment.  It  is  true  that  milk  is  altered  by  heating  but 
careful  investigation  by  many  observers  has  established  the  fact  that  the 
changes  that  are  induced  depend  on  the  degree  of  heat  applied  and  on  the 
length  of  the  heating  period.  North  has  compiled  the  results  reported  by 
many  students  of  the  subject  and  has  made  a  graph,  Fig.  41,  illustrating 
the  most  important  changes  that  take  place  in  the  milk  and  the  effect  of 
heating  on  certain  disease  germs.  It  appears  that  the  salts  begin  to  be 


30'  40' 

Time  in  Minutes 

FIG.  41. — Time  and  temperature  for  milk  pasteurization,  C.  F.  North. 

affected  when  the  milk  is  heated  to  170°F.  for  40  min.  and  in  less  time  as 
the  temperature  of  heating  rises  till  at  176°F.,  heating  for  1  min.  affects 
them.  The  principal  changes  that  occur  are  the  precipitation  of  calcium 
and  magnesium  salts  and  a  great  part  of  the  phosphorus  together  with  a 
decrease  in  organic  and  an  increase  in  inorganic  phosphorus.  The  albu- 
min is  more  sensitive  to  heat;  it  is  injured  by  heating  it  for  30  min.  at 
149°F.,  or  for  10  min.  at  158°F.  and  in  correspondingly  less  time  at  higher 
temperatures. 

The  enzymes,  the  figure  shows,  may  be  heated  to  149°F.  for  20  min. 


280  CITY  MILK  SUPPLY 

or  to  145°F.  for  30  min.  without  suffering  injury  but  longer  periods  of 
heating  at  lower  temperatures  affect  them  harmfully.  According  to 
Kastle  enzymes  cannot  be  exposed  many  minutes  to  temperatures  be- 
tween 149°F.  and  158°F.  without  weakening  their  activity  nor  to  tem- 
peratures between  158°F.  and  176°F.  for  more  than  a  brief  interval  without 
being  destroyed.  Tuberculosis,  typhoid  fever  and  diphtheria  germs  are 
all  killed  by  heating  the  milk  for  20  min.  at  140°F.  or  in  much  less  time  at 
higher  temperatures.  In  actual  practice  a  considerable  margin  of  safety 
is  taken.  By  the  holder  process  the  milk  is  commonly  heated  to  145°F. 
for  20  to  45  min.  The  Danes  in  using  the  flash  method  in  their  cream- 
eries heat  the  cream  and  skim-milk  to  176°F.  and  the  Chicago  regulations 
require  heating  for  1  min.  at  165°F.  The  cooked  taste  appears  in  milk  if  it 
is  heated  to  158°F.  for  20  min.  or  for  a  less  prolonged  exposure  at  higher 
temperatures.  The  cream  line  is  affected  by  heating  the  milk  for  50  min. 
to  140°F.  and  for  1  min.  at  155°F.  The  most  important  point  brought 
out  by  the  chart,  from  a  practical  standpoint  is,  that  contained  within 
the  tuberculosis  and  the  cream  lines  is  a  safety  zone  for  heating  milk,  for 
when  the  intersection  of  a  vertical  minute  line  with  a  horizontal  tempera- 
ture line  falls  within  the  zone,  milk  can  be  heated  to  that  point  without 
danger  of  injuring  it.  Besides  the  changes  delineated  by  North  others 
that  are  brought  about  by  heating  are  the  rendering  of  the  casein  less 
readily  coagulable  by  rennin  and  less  easily  and  more  slowly  acted  on  by 
pepsin  and  pancreatin.  If  milk  is  heated  in  metal  containers  to  high  tem- 
peratures, the  milk  takes  a  brownish  cast  which  is  thought  to  be  due  to 
caramelization  of  the  lactose  as  a  result  of  a  little  of  the  milk  coming  into 
contact  with  the  hot  metal  and  being  scorched. 

It  has  been  contended  that  owing  to  these  several  changes  milk 
is  made  less  digestible  by  pasteurization  but  the  careful  observations  of 
physicians  shows  that  this  is  not  so  with  milk  pasteurized  at  temperatures 
now  in  use. 

Suitability  of  Pasteurized  Milk  for  Infant  Feeding. — Whether  or  not 
pasteurized  milk  is  suitable  for  infant  feeding  has  excited  a  world  of  dis- 
cussion. It  is  the  general  belief  that  children  fed  on  such  milk  do  not 
contract  diarrheal  diseases,  nevertheless  its  use  has  been  condemned  by 
many  physicians  on  the  ground  that  it  is  the  cause  of  rickets  and  scurvy 
and  by  some  on  the  ground  that  the  enzymes  are  killed.  With  regard 
to  the  enzymes  in  milk  it  may  be  said  that  as  yet  it  is  not  known  to  what 
extent  they  are  a  part  of  the  milk  itself  and  to  what  extent  they  are  an 
elaboration  of  the  bacteria  of  the  udder.  The  evidence  seems  clear  that 
they  are  not  injured  at  the  temperatures  used  in  modern  pasteurization. 
It  cannot  be  said  that  final  opinion  has  been  reached  as  regards  feeding 
very  young  children  pasteurized  milk  but  the  tendency  is  to  take  a  con- 
servative position  in  the  matter.  On  the  one  hand  is  the  evidence  that  in 
Europe  milk  charities,  under  medical  direction,  on  a  large  scale  have  used 


THE  MILK  CONTRACTOR  281 

milk  pasteurized  at  high  temperatures  without  undue  prevalence  of 
rickets  and  scurvy  among  the  children,  and  the  like  experience  of  child 
welfare  stations  in  this  country  using  milk  pasteurized  at  low  temperatures. 
On  the  other,  statistics  are  offered  from  hospitals  and  other  sources  to  the 
effect  that  out  of  a  considerable  number  of  babies  who  developed  rickets 
and  scurvy  a  considerable  percentage  were  being  fed  pasteurized  milk 
prior  to  the  onset  of  the  disease.  The  studies  of  Hess  which  were  made  at 
a  New  York  institution  where  the  babies  remained  for  a  year  or  more 
and  were  weighed  and  measured  at  regular  intervals,  have  made  plain 
the  relation  between  pasteurized  milk  and  infantile  scurvy.  He  finds 
the  disease  belongs  to  the  same  class  as  beriberi  and  others  that  are  due 
to  the  continued  use  of  a  food  that  is  deficient  in  some  essential  substance. 
Pasteurized  milk  is  this  sort  of  food  for  its  antiscorbutic  vitamines  are 
partially  destroyed  in  the  pasteurizing  process  and  so  when  babies  are  fed 
on  such  milk,  unless  an  antiscorbutic  such  as  orange  juice  is  given  with 
it,  they  develop  a  subacute  type  of  scurvy.  This  is  the  most  common 
form  of  the  disorder  and  is  easily  overlooked.  Babies  derive  antiscor- 
butic material  from  their  mothers  but  when  artificial  feeding  is  begun 
this  protection  is  lost.  Since  pasteurized  milk  still  contains  some  vita- 
mines  it  takes  an  infant  that  is  fed  on  it  without  antiscorbutics,  7  or  8 
months  to  develop  scurvy  from  its  use.  During  the  development  of  the 
disease  the  growth  of  the  baby  is  usually  arrested.  The  weight  stops  in- 
creasing and  remains  stationary  for  weeks  or  months,  but  the  child  re- 
sponds quickly  to  orange  juice  or  its  equivalent,  often  making  supergrowth 
till  it  attains  the  correct  weight  for  its  age.  An  underfed  child,  if  given 
the  amount  of  food  it  needs,  may  respond  to  this  impulse  and  increase 
its  weight  throughout  the  scorbutic  condition.  Measurements  show  that 
the  growth  of  the  infant  in  length  is  retarded  during  a  long  attack  of 
scurvy  but  that  on  the  administration  of  "orange  juice,  growth  begins 
again  as  vigorously  as  ever.  Hess  recommends  the  use  of  pasteurized 
milk  in  infant  feeding  on  account  of  the  security  which  it  affords 
against  infections,  but  he  advises  that  when  infants  are  fed  exclusively 
on  a  diet  of  pasteurized  milk,  antiscorbutics  should  be  given  far  earlier 
than  at  present,  even  as  early  as  at  the  end  of  the  first  month  of  life. 
The  question  whether  an  infant  ought  or  ought  not  to  have  pasteurized 
milk  is  purely  a  medical  one  and  should  be  settled  by  the  orders  of  the 
physician.  As  illustrative  of  the  results  obtained  in  the  use  of  pasteurized 
milk  in  child  welfare  stations  those  obtained  from  April  24,  1911,  to  Oct. 
24,  1912,  at  the  George  M.  Oyster,  Jr.  Milk  Philanthropy  in  Washington, 
D.  C.,  are  presented. 

Of  the  babies  131,  or  18.8  per  cent,,  were  born  out  of  wedlock  and 
were  regarded  as  burdens  by  those  having  them  in  charge. 

The  reasons  given  for  bottle  feeding  by  those  who  brought  the  babies 
to  the  station  were: 


282  CITY  MILK  SUPPLY 

Per   cent. 

Mother  obliged  to  go  out  to  work 25 . 40 

Mother  able  to  supply  by  nursing  but  part  of  the  milk 

necessary 25 . 08 

Mother's  milk  failed .  15.40 

Mother  too  ill  to  nurse 9.16 

Mother  dead 7.50 

Mother's  milk  not  nourishing 7 . 50 

Mother  deserted  the  baby Ji  5 . 80 

Mother  never  able  to  nurse 4.16 

In  the  entire  period  20  physicians  and  two  to  four  graduate  nurses 
cooperated  in  the  work.  The  nurses  gave  their  entire  time  and,  besides 
being  present  and  helping  in  the  examination  of  babies  at  the  stations, 
visited  the  homes  of  the  children. 

In  all  1,128  babies  were  prescribed  for  and  377,500  bottles  of  milk 
distributed.  The  records  of  110  babies  were  not  complete.  Of  the  1,108 
others  it  was  found : 

557   babies    prescribed    pasteurized    milk    exclusively 

showed  an  average  net  gain  of 0.4077  oz.  per  baby  per  day. 

351  babies  prescribed  raw  milk  exclusively  showed  an 

average  net  gain  of 0 . 4030  oz.  per  baby  per  day. 


Difference  in  favor  of  pasteurized  milk. 0.0047  oz.  per  baby  per  day. 

110  babies  prescribed  both  pasteurized  and  raw  milk  at  different  times 
showed : 

On  pasteurized  milk  an  average  net  gain. of 0.4607  oz.  per  baby  per  day. 

On  raw  milk  an  average  net  gain  of 0.4312  oz.  per  baby  per  day. 


Difference  in  favor  of  pasteurized  milk 0.0295  oz.  per  baby  per  day. 

Milk  for  Babies  a  Special  Milk. — It  is  now  recognized  that  in  our 
large  cities  it  is  not  feasible  to  bring  the  whole  milk  supply  up  to  the  stand- 
ard of  that  required  for  infant  feeding.  The  procuring  of  a  supply  of 
babies  milk  is  a  special  problem  of  city  milk  supply  and  this  should  be 
remembered  in  relation  to  pasteurization.  Pasteurization  protects  babies 
from  diarrheal  diseases,  typhoid  fever,  diphtheria,  scarlet  fever,  and  from 
bovine  tuberculosis  and,  if  in  the  opinion  of  some  physicians  this  advan- 
tage is  outweighed  by  other  considerations  or  at  least  in  some  cases 
makes  the  use  of  raw  milk  advisable,  it  does  not  follow  that  for  these 
reasons  older  children  and  adults  should  surrender  the  protection  from 
communicable  disease  that  the  use  of  pasteurized  milk  affords. 

Pasteurization  an  Additional  Process. — It  has  been  urged  that  pas- 
teurization is  an  additional  process  to  those  already  in  use  in  preparing 
milk  for  the  market  and  involves  exposing  it  to  new  sources  of  contamina- 
tion and  to  the  possibility  of  infection  from  another  group  of  workers  in 
the  milk  plants.  That  there  was  some  slight  grounds  for  these  fears 


THE  MILK  CONTRACTOR  283 

must  be  admitted  but  practically  they  have  not  proved  serious  obstacles 
to  the  success  of  the  process.  Galloway  tells  that  in  a  plant  in  Portland, 
Ore.,  which  was  pasteurizing  milk  by  the  holder  method  at  140°F.,  the 
milk  entering  the  pasteurizer  showed  a  bacterial  count  of  50,000  per 
cubic  centimeter  and  that  issuing  from  it  200,000.  Investigation  showed 
that  the  inside  of  the  pipes  were  so  badly  corroded  and  pitted  that  the 
machine  could  not  be  kept  clean.  In  a  Milk  Plant  Letter  of  the  U.  S. 
Department  of  Agriculture  it  is  stated  that  the  pasteurizer  is  one  of 
the  most  difficult  pieces  of  machinery  to  keep  clean  but  that  it  must  be 
kept  so,  for  if  it  is  not,  on  the  inside  a  cooked  layer  forms  which  daily 
grows  worse.  The  self-interest  of  the  contractor  operates  to  keep  down 
this  sort  of  thing  for  it  is  likely  to  make  itself  known  to  customers  in  a 
product  so  inferior  that  they  reject  it.  The  watchful  eye  of  an  alert  in- 
spector is  a  good  corrective  to  uncleanliness.  Epidemics  have  seldom 
been  traced  to  pasteurized  milk  and  of  the  few  that  have,  only  a  small 
percentage  were  thought  to  be  derived  from  the  men  who  were  doing 
the  pasteurizing. 

Milk  Liable  to  Recontamination  after  Pasteurization. — Except  when 
the  pasteurization  is  done  in  the  bottle  there  is  opportunity  for  the  milk 
to  be  re' contaminated  in  the  bottling  and  capping.  In  fact  before  it  had 
been  ascertained  that  lactic  acid  bacteria  survive  pasteurization  at  low 
temperatures,  several  observers  were  inclined  to  attribute  the  souring  of 
commercially  pasteurized  milk  to  this  recontamination,  and  brought  forth 
the  suggestion  that  instead  of  depending  on  this  chance  method  to  bring 
about  the  desirable  souring  of  pasteurized  milk  it  would  be  well  to  assure 
it  by  inoculating  the  pasteurized  milk  with  a  lactic  culture.  This  pro- 
cedure was  never  practised.  No  doubt  some  contamination  with  lactic 
and  other  germs  does  occur  after  the  milk  is  pasteurized,  and  this  being 
the  case  it  must  be  admitted  that  there  is  an  opportunity  also,  for  the 
pasteurized  milk  to  be  infected  either  by  the  men  who  bottle  and  cap  it, 
provided  any  of  them  are  sick  with,  or  are  carriers  of,  infectious  disease, 
or  by  filling  the  milk  into  insterile  infected  bottles  and  other  containers. 
Bottle  infection  of  pasteurized  milk  was  suspected  to  have  actually 
occurred  in  Rockford,  111.,  in  1913.  The  infection  of  milk  subsequent 
to  pasteurization  and  before  delivery  to  the  consumer  is  very  unusual 
but  it  may  occur,  and  both  health  officers  and  the  public  should  know 
that  while  the  chances  of  pasteurized  milk  becoming  a  medium  for  the 
spread  of  communicable  disease  are  remote,  they  nevertheless  exist. 
So  long  as  it  was  believed  that  germs  grew  more  rapidly  in  pasteurized 
than  in  raw  milk,  there  was  considerable  concern  over  dangers  that  it 
was  conceived  might  arise  from  the  contamination  of  pasteurized  milk 
in  the  home  of  the  consumer,  but  anxiety  on  this  score  has  dissipated. 

Overconfidence  in  Pasteurized  Milk. — The  last  objection  to  the  use 
of  pasteurized  milk  that  merits  notice  is  the  contention  that  pasteuriza- 


284  CITY  MILK  SUPPLY 

tion  begets  a  sense  of  false  security  on  the  part  of  the  consumer,  that  he 
comes  to  believe  that  since  the  milk  has  been  pasteurized  it  is  absolutely 
safe  and  will  remain  so  in  his  hands.  Exuberant  advertising  has  perhaps 
had  some  tendency  to  lead  the  public  to  trust  pasteurized  milk  too 
implicitly  but  in  general  the  faith  placed  in  pasteurized  milk  is  warranted 
and  much  good  results  from  allaying  the  mistrust  of  anxious  mothers 
that  sickness  may  be  lurking  in  the  milk  they  are  feeding  their  children. 
Pasteurization  and  the  Score  Card. — About  1908  the  tide  of  criticism 
that  had  been  running  against  pasteurization  began  to  subside  and  now 
the  process  has  emerged  and  stands  well-favored.  Many  factors 
brought  about  the  change  but  seven  were  particularly  important. 

1.  The  so-called  official  score  card  began  to  be  widely  used  and  to  prove 
itself  a  helpful  corrective  of  the  dirty  dairies  and  insanitary  methods  it 
was  so  greatly  feared  pasteurization  would  perpetuate.     The  score  card 
and  pasteurization  work  together  nicely,  the  one  impels  the  dairy  farmer 
to  produce  milk  in  a  clean  place  and  in  a  sanitary  manner  and  the  other 
enhances  the  keeping  quality  of  the  milk  so  produced  and  reduces  the 
chances  of  contracting  contagion  from  it  almost  to  the  vanishing  point. 

2.  Milk  Liable  to  Bovine  Infection. — Sanitarians  finally  realized  that 
the  cow  is  very  subject  to  certain  diseases  which  infect  the  milk  with  their 
germs.     Furthermore,  they  found  that  in  some  of  the  infectious  diseases 
of  man,  the  ambulatory  cases  and  bacillus  carriers  were  more  common  and 
more  potent  factors  in  the  spread  of  contagion  than  had  been  believed 
and  that  the  operation  of  these  infectious  agents  was  so  insidious  that  it 
was  apparent  that  even  those  dairymen  who  were  doing  their  utmost  to 
protect  their  milk  from  infection  would  at  times  fail  in  their  efforts. 

The  germ  diseases  of  the  cow  which  are  so  common  as  to  have  an  im- 
portant bearing  on  the  pasteurization  problem  are  tuberculosis,  contagious 
abortion  and  certain  forms  of  mammitis.  As  it  became  known  how  prev- 
alent bovine  tuberculosis  is,  in  the  herds  of  dairy  districts  where  the  chief 
business  is  supplying  the  city  milk  trade,  and  as  it  came  to  be  understood 
that  it  would  be  years  before  the  disease  could  be  eradicated,  it  was  seen 
that  pasteurization  would  greatly  minimize  the  danger  that  children  ran 
in  drinking  milk.  The  germs  of  contagious  abortion  are  common  in  mar- 
ket milk;  so  far  as  known  they  are  not  pathogenic  for  man  but  Schroeder 
has  pointed  out  that  on  general  principles  it  is  not  well  for  one  race  to  be 
constantly  exposed  to  germs  that  are  pathogenic  for  another  so  that,  if  this 
view  is  accepted,  an  additional  reason  for  pasteurizing  milk  for  human 
consumption  is  found.  Both  bovine  tuberculosis  and  contagious  abor- 
tion inflict  much  loss  on  the  owners  of  farm  animals  and  as  the  germs  of 
these  diseases  are  found  in  skim-milk  and  whey  from  creameries  and 
cheese  factories  these  products  should  be  pasteurized  before  being  returned 
to  the  farm. 

Septic  sore  throat  powerfully  influenced  sanitarians  to  accept  pasteur- 


THE  MILK  CONTRACTOR  285 

ization.  This  disease  was  first  recognized  in  this  country  in  1911  when  it 
was  the  cause  of  a  widespread  epidemic  in  Boston.  One  of  the  most  care- 
fully supervised  dairies  in  New  England  was  the  victim  of  its  onslaught. 
This  epidemic  was  followed  by  other  extensive  outbreaks  of  the  same 
disease  in  several  of  the  principal  cities  of  the  United  States.  While 
in  some  instances  the  sanitary  standards  of  the  dairies  that  were  attacked 
were  not  commendable,  in  others  they  were  excellent  and  it  was  evident 
that  the  disease  might  get  into  a  dairy  without  those  responsible  for  the 
conduct  of  the  business  being  aware  of  its  presence,  consequently  they 
could  not  justly  be  held  responsible  for  distributing  it.  When  septic 
sore  throat  first  began  to  be  recognized  it  was  very  strongly  suspected 
that  the  streptococci  that  caused  it  were  derived  from  the  udders  of  cows 
suffering  with  mammitis.  As  it  was  known  that  in  most  large  herds 
there  were  usually  one  or  more  cows  that  had  the  disease,  the  question 
arose  as  to  what  extent  these  animals  menaced  the  public  health.  At 
that  time  the  evidence  had  not  been  collected  that  it  is  those  cows  whose 
udders  have  been  infected  with  streptococci  by  persons  having  septic 
sore  throat,  or  by  carriers  of  the  Smith  streptococcus  and  there  was 
serious  concern  over  the  possibility  that  all  gargety  cows  might  be  more 
dangerous  than  had  hitherto  been  believed.  Boards  of  health  were  active 
and  attempted  to  exclude  from  the  market  milk  that  had  a  high  cellular 
content  but  this  position  was  found  untenable,  because  it  was  discovered 
that  the  milk  of  perfectly  healthy  cows  as  well  as  that  of  those  suffering 
from  mammitis,  at  times  had  a  high  cellular  count.  Then  the  association 
of  long-chained  streptococci  with  a  high  cell  count  in  the  milk  was  ad- 
vanced as  evidence  that  the  milk  came  from  a  cow  having  mammitis  and 
so  was  potentially  dangerous,  which  sufficed  to  debar  the  milk  from  the 
market.  However,  this  theory  was  not  at  once  universally  accepted  so 
that  there  was  neither  a  certain  way  o£  telling  whether  a  given  sample 
of  market  milk  was  in  part  derived  from  cows  that  had  mammitis,  nor 
for  telling  whether  any  streptococci  that  were  observed  in  the  milk  were 
dangerous  to  man.  To  such  a  situation  pasteurization  offered  a  safe 
and  welcome  solution. 

3.  Impossible  to  Protect  Milk  from  Human  Infection. — The  situation 
with  regard  to  human  disease  was  quite  as  serious  as  with  animal  diseases. 
For  instance,  Lumsden  in  1908  stated  that  on  the  assumption  that  there 
were  seven  persons  on  each  of  the  1,000  dairy  farms  supplying  Washing- 
ton, D.  C.,  there  would  be  on  these  farms,  since  at  that  time  about  one 
person  in  every  300  in  the  United  States  every  year  had  typhoid  fever, 
25  new  cases  of  this  one  disease  yearly.  Bolduan  states  that  the  milk 
supply  of  New  York  City  in  1912  came  from  40,000  farms  and  that  in  one 
way  or  another  200,000  people  handled  the  milk.  The  incidence"  of 
typhoid  fever  around  New  York  varied  from  150  to  200  cases  per  100,000 
annually  so  that  these  people  who  handled^the  milk  would  furnish  300 


286  CITY  MILK  SUPPLY 

to  400  new  typhoid  fever  cases  every  year.  If  it  be  supposed  that  only 
2  per  cent,  of  these  became  chronic  carriers  and  that  they  remained  such 
for  but  15  years  there  would  be  90  to  120  typhoid  carriers  continually 
menacing  the  milk  supply  of  New  York  City. 

The  ability  of  pasteurization  to  protect  a  city  from  communicable 
disease  is  well-illustrated  by  the  experience  of  Berkeley  during  the  Rich- 
mond, Cal.,  outbreak  of  typhoid  fever.  Geiger  and  Kelly  report  that 
from  a  certain  dairy  that  employs  20  .men  and  keeps  300  cows  Richmond 
receives  90  gal.  of  milk  which  was  used  by  500  people  daily  and 
Berkeley  600  gal.  which  was  delivered  to  2,000  homes  where  it  was  used 
by  at  least  6,000  people.  In  Richmond,  where  the  milk  was  used  raw, 
12  cases  of  typhoid  fever  developed  which  led  to  its  being  promptly 
withdrawn  from  the  public. 

In  Berkeley,  where  the  milk  was  pasteurized,  not  a  single  case  ap- 
peared. The  milk  was  found  to  have  been  infected  by  the  head  milker 
who,  a  little  before  the  source  of  the  contagion  was  traced  out,  had  been 
taken  to  a  hospital  where  he  gave  a  positive  Widal  reaction. 

It  is  certain  that  even  those  dairymen  who  are  most  zealous  in  their 
efforts  to  protect  their  milk  from  infection  will  at  times  fail.  Sometimes 
the  afflicted  person  may  begin  spreading  disease  germs  while  his  malady 
is  still  in  the  prodromal  stage;  the  disease  may  not  be  recognized  till 
it  is  well  advanced  or  it  may  never  be  detected,  besides  which  tempo- 
rary, acute  and  chronic  bacillus  carriers  may  every  one  of  them  spread 
contagion  innocently  and  unobserved.  Indeed,  to  pasteurize  milk  is 
the  only  reliable  way  to  prevent  it  from  sometimes  becoming  the  vehicle 
of  contagion.  Communities  that  use  raw  milk  will  inevitably  have  oc- 
casional outbreaks  of  milk-borne  infectious  disease. 

4.  Pasteurization  at  Low  Temperatures  Destroys  Disease  Germs.— 
A  fourth  factor  in  convincing  people  that  pasteurization  might  be  prac- 
tical along  right  lines  was  the  experimental,  chemical  and  bacteriological 
studies  of  several  investigators.  As  has  been  indicated  previously,  the 
chemical  changes  that  take  place  in  pasteurization  of  milk  at  low  tem- 
peratures are  quite  different  from  those  that  occur  at  the  higher  ones 
that  were  in  use  when  the  pasteurization  of  milk  was  first  begun.  In- 
deed, milk  is  little  changed  by  heating  it  for  30  to  45  min.  at  145°F.,  a 
temperature  and  exposure  that  bacteriological  studies  have  established 
as  sufficient  to  kill  the  non-spore-bearing  pathogenic  organisms  that  occur 
in  milk. 

Up  to  1899,  it  was  thought  necessary  in  order  to  kill  the  tubercle 
bacillus  to  either  heat  milk  for  a  moment  to  high  temperatures,  as  at  the 
175°  to  185°F.  advocated  by  Bang,  or  to  heat  it  to  155°F.  for  20  min. 
In  that  year  Theobald  Smith  announced  that  heating  milk  to  140°F. 
for  20  min.  sufficed  to  kill  the  germs,  if  the  milk  was  stirred  or  kept 
covered  during  heating  to  prevent  the  formation  of  a  pellicle  on  the  sur- 


THE  MILK  CONTRACTOR  287 

face.  The  importance  of  the  fact  was  perceived  at  once  for  heating  to 
155°F.  for  20  min.  affects  the  albumin,  enzymes  and  cream  line  and  is 
nearly  high  enough  to  impart  a  cooked  flavor  to  milk  whereas  at  the  lower 
temperature  trouble  with  these  constituents  and  properties  is  avoided. 
Other  observers,  notably  Hesse,  Russell  and  Hastings,  and  Rosenau,  con- 
firmed Smith's  findings.  The  thermal  death  points  of  the  common  dis- 
ease germs  have  been  determined  by  several  bacteriologists.  In  this 
country  the  findings  of  Rosenau  are  accepted.  They  are  published  in 
Hygienic  Laboratory  Bulletin  42  and  show  that: 

"The  tubercle  bacillus  loses  its  virulence  and  infective  power  for  guinea-pigs 
when  heated  in  milk  at  140°F.  for  20  min.,  or  at  149°F.  for  a  much  shorter  time; 
in  other  words,  it  may  be  considered  dead. 

"The  typhoid  bacillus  when  heated  for  2  min.  at  140°F.  is  killed;  the  great 
majority  of  these  organisms  are  killed  by  the  time  the  temperature  reaches  138°F. 
and  few  survive  to  140°F. 

"The  diphtheria  bacillus  succumbs  at  comparatively  low  temperature;  it 
often  fails  to  grow  after  heating  to  131°F.;  occasionally  some  survive  until  the 
milk  reaches  140°F. 

"The  cholera  vibrio  is  usually  destroyed  at  131°F.  and  only  once  survived 
to  140°F. 

'  'Both  the  Shiga  and  Flexner  types  of  dysentery  bacillus  were  experimented 
with.  The  bacillus  is  somewhat  more  resistant  to  heat  than  the  typhoid  bacillus 
but  the  great  majority  of  the  dysentery  germs  are  killed  by  the  time  the  milk 
reaches  140°F.  They  sometimes  withstand  heating  to  140°F.  for  5  min.;  heating 
to  this  temperature  for  10  min.  always  kills  them. 

"The  evidence  with  regard  to  M.  melitensis  is  meager.  The  organism  is  not 
destroyed  by  heating  to  131°F.  for  a  short  time;  the  great  majority  of  these  micro- 
cocci  are  killed  at  136.4°F.  and  all  are  killed  at  140°F. 

"A  temperature  of  140°F.  for  20  min.  is  sufficient  to  destroy  the  virus  of 
scarlet  fever,  streptococci  and  other  pathogenic  organisms. 

"Milk  heated  to  140°F.  and  maintained  at  that  temperature  for  20  min.  may 
be  considered  safe  so  far  as  conveying  infection  with  any  of  these  organisms  is 
concerned." 

These  laboratory  findings  were  tested  in  1912  on  a  commercial  scale 
by  Schorer  and  Rosenau  who  had  placed  at  their  disposal  for  the  purpose, 
a  pasteurizing  plant  that  was  to  be  dismantled.  It  was  equipped  to 
handle  8,000  Ib.  of  milk  an  hour  by  the  holder  process.  The  principal 
parts  of  the  system  were  the  receiving  vat,  the  milk  pump,  the  heater 
and  the  holder.  Four  runs  were  made  with  milk  heavily  seeded  with 
cultures  of  diphtheria,  typhoid  fever,  bovine  and  human  tuberculosis. 
The  results  obtained  in  these  experiments  are  briefly  set  forth  in  Table  83. 

From  these  experiments  it  was  concluded  that  by  heating  milk  to 
140°F.  and  holding  it  at  that  temperature  for  20  min.  the  germs  of  diph- 
theria, typhoid  fever  and  tuberculosis  are  surely  killed  but  that  probably 
practical  conditions  are  best  met  by  pasteurizing  at  145°F.  for  30  to  45 


288 


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THE  MILK  CONTRACTOR  289 

min.  Several  holding  tanks  in  series  are  more  trustworthy  than  one,  for 
the  first  tank  acts  as  an  equalizer  and  the  others  hold  the  milk  at  the 
desired  temperature.  Pasteurizing  plants  should  be  under  official  con- 
trol for  they  are  too  important  in  preserving  the  public  health  to  be  left 
to  the  caprices  of  the  individual. 

5.  Advent  of  the  Holder  Process.— The  fifth  important  factor  in 
establishing  faith  in  pasteurization  was  the  development  of  the  holder 
process.     With  the  perfection  of  machinery  that  made  commercially 
available  a  process  of  pasteurization  which  was  endorsed  by  medical  men 
as  effective  and  as  not  materially  altering  the  milk,  public  confidence  in 
pasteurization  was  largely  restored. 

6.  Success  of  Child  Welfare  Stations. — The  convincing  work  of  child 
welfare  stations  influenced  the  public  favorably  toward  pasteurization. 
The  pioneer  work  of  Hoplik,  the  widely  advertised  work  of  Straus  and 
of  a  shoal  of  others  in  all  parts  of  the  United  States  who  distributed 
pasteurized  milk  to  the  children  of  the  poor  with  good  results,  familiarized 
people  with  this  new  product  and  satisfied  them  that  it  was  safe. 

7.  Finally,  it  became  appreciated  that  if  any  large  percentage  of  the 
entire  milk  supply  of  the  public  was  to  be  pasteurized  it  must  be  done 
outside  of  the  home.    ,  A  small  amount  of  milk  might  be  pasteurized  for 
children  but  it  was  too  much  of  a  tax  on  the  overburdened  housewife  to 
expect  her  to  pasteurize  the  milk  of  the  whole  family.     Furthermore,  it 
was  as  desirable  that  the  milk  consumed  in  restaurants  and  hotels  should 
be  pasteurized  as  that  the  milk  drunk  at  home  should  be,  and  it  was 
unlikely  that  this  would  come  about  except  the  milk  should  be  sold 
already  pasteurized  by  the  contractor. 

Pasteurizing  Machines. — The  machines  that  are  used  for  pasteurizing 
should  be  simple,  durable  and  easily  cleaned.  An  intricate  machine  is 
more  liable  to  accident  than  is  a  simple  one;  therefore  it  is  not  as  good, 
for  it  must  be  dependable  since  the  efficiency  of  the  pasteurization  is  inter- 
fered with  by  interruptions.  The  machine  ought  to  be  durable  because 
it  receives  constant  wear  from  daily  use  which  it  must  be  able  to  bear 
well  or  else  the  money  that  is  spent  in  repairs  and  replacements  becomes 
an  excessive  tax  on  the  business.  As  heated  milk  is  prone  to  stick  to 
pasteurizers  they  must  needs  have  a  thorough  cleaning  daily.  This  re- 
quires labor  and  money ;  so  to  keep  the  expenditure  thereof  at  a  minimum 
the  machine  should  be  easily  cleaned.  Moreover,  a  pasteurizer  with 
difficultly  accessible  parts  will  not  be  thoroughly  cleaned  and  so  will  be 
likely  to  contaminate  the  milk.  In  type,  the  pasteurizer  should  be 
adapted  to  the  business.  A  small  dairy  with  a  fixed  trade  needs  a  differ- 
ent machine  from  a  large  one  with  a  rapidly  expanding  business.  What- 
ever pasteurizer  is  chosen  it  should  have  a  capacity  greater  than  the  de- 
mand that  will  be  made  upon  it  for  forcing  a  machine  always  results  in 
a  poor  product.  Pasteurizing  is  done  either  in  vats  or  by  running  thin 

19 


290  CITY  MILK  SUPPLY 

sheets  of  milk  over  hot  surfaces;  these  are  better  heated  by  a  hot  water 
jacket  than  by  steam  for  the  temperature  is  more  easily  controlled  and 
the  milk  is  less  likely  to  be  scorched. 

A  pasteurizing  unit  proper  may  consist  of  one  or  of  two  parts.  In 
the  flash  process  there  is  only  the  heater;  in  the  holder  process  there  is 
a  heater  and  also  a  holder  or  a  retarder,  while  the  bottle  process  accom- 
plishes the  heating  and  holding  in  a  single  machine.  The  different  types 
of  pasteurizers  have  been  grouped  according  to  their  mode  of  operation 
by  Kilbourne  and  also  by  Ayres.  The  following  arrangement  follows 
their  suggestions. 

Type  1. — The  Danish  heater.  In  this  machine  there  is  a  revolving 
paddle  in  a  milk  chamber  that  has  a  water  jacket  which  is  filled  by  in- 
jecting steam  from  three  jets  till  it  condenses  and  fills  the  jacket  with 
hot  water.  Milk  is  fed  through  an  inlet  into  the  bottom  of  the  chamber 
and  by  the  centrifugal  action  of  the  paddle  is  thrown  against  the  sides 
of  the  hot  water  jacket,  being  forced  out  at  the  top  through  the  milk 
outlet  pipe  in  which  is  a  thermometer  for  taking  the  temperature  of  the 
outgoing  pasteurized  milk. 

The  advantages  of  this  type  are  its  small  cost,  ease  of  cleaning  and 
power  to  lift  the  milk  about  4  ft.  to  a  holder  or  cooler. 

Type  2. — This  pasteurizer  consists  of  a  cylinder  surrounded  by  a  water 
jacket  that  is  heated  by  a  steam  discharge  into  the  water  pipe  connected 
thereto.  Within  the  cylinder  is  a  revolving  drum  to  which  milk  is  carried 
through  the  milk  inlet,  and  which  in  revolving,  by  centrifugal  action 
spreads  the  milk  over  its  surface  in  a  film,  between  it  and  the  hot  water 
jacket,  finally  discharging  the  milk  through  the  outlet  with  force  to  raise 
it  several  feet. 

Type  3. — This  is  a  machine  consisting  of  a  conical  surface  that  is 
constantly  wiped  by  a  tape  attached  to  a  revolving  frame  and  that  is 
heated  by  steam  discharging  into  hot  water  beneath  the  cone.  Milk  is 
run  through  the  bottom  of  a  reservoir  over  the  top  of  the  cone  and  flows 
down  its  sides,  being  kept  from  burning  by  the  action  of  the  tape,  into 
a  trough  whence  it  is  carried  to  the  holder  or  cooler. 

Type  4. — Machines  in  which  the  milk  flows  with  a  rotary  motion, 
between  two  or  more  water-heated  upright  cylindrical  surfaces.  Some 
of  these  machines  are  constructed  on  the  regenerative  principle  by  which 
the  outgoing  hot  milk  is  utilized  to  warm  the  incoming  cold  milk,  thereby 
economizing  heat.  The  most  satisfactory  machines  of  the  fourth  type 
are  those  that  operate  with  large  enough  volumes  of  water  to  allow  the 
water  to  be  used  at  low  temperatures. 

Type  5. — These  machines  are  coils  of  double  tubes,  the  internal  one 
carrying  the  milk  and  the  encasing  one  hot  water  that  is  heated  by  a 
steam  jet  introduced  to  the  water  before  it  enters  the  coil.  In  this  ap- 
paratus the  hot  water  flows  in  a  direction  opposite  to  that  of  the  milk, 


THE  MILK  CONTRACTOR  291 

thus  utilizing  the  maximum  heating  power  of  the  water  and  raising  the 
temperature  of  the  milk  gradually.  The  efficiency  of  machines  of  this 
type  depends  on  securing  a  slow  enough  flow  of  the  milk  and  sufficient 
heating  surface  to  certainly  heat  all  of  the  milk  to  the  required  tempera- 
ture. It  is  important  that  these  pasteurizers  shall  be  so  built  that  there 
shall  be  no  danger  of  intermingling  of  the  milk  and  water  through  leakage, 
and  so  that  they  can  be  easily  taken  apart  for  thorough  cleaning.  The 
advantages  of  this  type  of  pasteurizers  are  that  they  are  built  so  strongly 
that  they  can  be  sterilized  by  steam  under  pressure  and  that  they  are 
constructed  in  sectional  units  whose  capacity  can  be  increased  by  the 
addition  of  more  units  as  the  growth  of  business  demands  it.  An  objec- 
tion to  this  apparatus  is  that  the  pipes  are  so  slightly  inclined  from  the 
horizontal  that  at  the  end  of  the  run  it  is  difficult  to  empty  all  the  milk 
from  the  machine. 

Type  6. — Various  makes  of  tanks  that  are  insulated  and  heated  by 
hot  water  jackets  or  in  some  patterns  by  revolving  screws  or  coils  of  pipe, 
are  extensively  used  for  pasteurizing  milk  on  a  small  scale.  The  extreme 
simplicity  of  the  vat  system  highly  recommends  it.  The  life  of  dairy 
machinery  is  short  because  of  the  rough  usage  it  must  necessarily  re- 
ceive. The  simple  tanks  may  outlast  the  more  complicated  heater  and 
holders  and  therefore  cost  less.  They  are  also  economical  because  the 
tank  may  be  used  as  a  heater,  holder  and  cooler.  The  great  disadvantage 
is  that  it  takes  a  long  time  to  raise  the  milk  to  the  desired  temperature  and 
likewise  to  cool  it.  Besides,  unless  the  tank  is  kept  covered  the  loss  from 
evaporation  is  considerable.  The  advantage  of  the  tanks  is  that  the 
heating  of  the  milk  may  be  checked  right  at  the  desired  temperature  and 
the  milk  held  there  till  the  tank  is  emptied.  When  the  tanks  are  used  for 
cooling,  cold  water  and  afterward  brine  is  pumped  through  the  jackets 
or  screws.  In  some  types  of  tanks  the  bearings  or  packing  boxes  of 
the  agitators  come  into  contact  with  the  milk,  and  contaminate  it  with 
oil.  While  this  is  perhaps  one  of  those  things  that  are  more  unsightly 
than  dangerous  it  should  be  avoided  if  for  no  other  reason  than  that  there 
is  some  slight  danger  of  the  oil  imparting  a  bad  flavor  to  the  milk. 

In  the  spray  vat  system  one  tank  is  contained  within  another  but  in- 
stead of  being  cooled  by  a  water  jacket  filling  the  space  between  the  inner 
and  outer  tank  it  is  cooled  by  a  spray  of  cold  water  from  a  pipe  that  runs 
along  its  upper  edge,  the  spray  being  delivered  in  such  a  way  that  the  jets 
unite  to  form  a  film  which  runs  down  the  outer  surface  of  the  inner  tank 
and  away  at  the  bottom.  The  milk  is  agitated  by  blades  affixed  to  a 
mechanism  that  travels  on  the  top  frame  of  the  vat,  thereby  eliminating 
all  danger  of  oil  contamination. 

Type  7. — There  is  a  tank  for  pasteurizing  milk  in  cans.  A  double 
row  of  cog  wheels  runs  the  full  length  of  the  tank  bottom  and  on  each 
wheel  is  placed  a  10-gal.  can  within  each  of  which  is  a  stationary  paddle, 


292  CITY  MILK  SUPPLY 

The  tank  is  filled  with  water  of  the  desired  temperature  and  the  wheels 
are  set  in  motion  by  a  drive  gear  at  the  end  of  the  tank.  Thus  the  cans 
revolve  and  the  milk  is  stirred  by  the  paddle.  When  the  proper  time  has 
elapsed  the  milk  is  poured  from  the  cans  over  a  cooler. 

Type  8. — For  pasteurizing  milk  in  bottles  two  types  of  heaters  are 
used.  The  first  is  a  tank  of  galvanized  iron  or  cement,  with  steam  pipes 
suitably  arranged  on  the  bottom  and  sides  for  heating  the  water  in  the 
tank  to  the  required  temperature.  The  carefully  sealed  bottles  are 
stacked  in  the  tank  and  covered  with  water  which  is  raised  to  the  pasteur- 
izing temperature  and  held  there  for  the  proper  period.  Such  apparatus 
is  inexpensive  and  makes  pasteurization  a  possibility  for  small  dairies. 

More  costly  machines  for  pasteurizing  milk  in  the  bottle  are  put  out 
by  the  manufacturers  of  beer-pasteurizing  machinery.  In  these  machines 
cases  of  bottled  milk  by  various  devices  are  subjected  to  showers  of  water 
that  gradually  rise  in  temperature  till  they  reach  the  pasteurizing  point, 
where  they  remain  stationary  for  J^  to  %  hr.,  after  which  the  temperature 
of  the  showers  is  reduced  till  the  milk  is  cooled  sufficiently  for  it  to  be  put 
in  cold  storage. 

The  great  advantage  of  pasteurizing  in  the  final  package  is  that  the 
cap,  bottle  and  milk  are  all  subjected  to  the  pasteurizing  temperature 
and  are  not  thereafter  exposed  to  contamination.  Besides  this,  the  loss 
from  evaporation  that  occurs  in  some  of  the  other  processes  of  pasteur- 
ization is  eliminated.  The  chief  disadvantage  is  the  cost.  The  pasteur- 
ization has  hitherto  been  done  in  small  units  which  is  an  expensive  way 
of  handling  the  milk.  The  caps  used  are  of  types  controlled  by  the 
several  manufacturers  thereof  so  that  they  are  costly  and  one  of  these 
patent  caps  chips  the  bottles  thereby  increasing  bottle  costs  which  are 
also  increased  by  breakage  resulting  from  the  strains  developed  by  rapid 
heating  and  cooling.  Most  of  the  processes  that  are  in  use  are  not  re- 
generative, consequently  they  are  unnecessarily  expensive  for  it  is  possible 
to  so  design  the  apparatus  that  the  water  which  is  warmed  in  cooling  the 
hot  milk  can  be  utilized  in  heating  up  the  cold.  A  good  grade  of  milk 
can  be  safely  pasteurized  in  the  bottle,  but  mixed  milk  collected  from  divers 
medium-class  producers  is  likely  to  be  in  part  made  up  of  the  strongly 
flavored  milk  of  cows  approaching  the  end  of  the  lactation  period  and  of 
milk  that  has  an  unpleasant  odor  derived  from  forage,  bacterial  growths 
and  other  sources  and  such  milk  is  apt  to  give  trouble  because  the  heating 
may  intensify  the  odors  to  the  detriment  of  the  milk  since  they  have  no 
chance  to  escape. 

The  process,  advocated  by  Ayres  and  Johnson,  of  bottling  hot  milk,  is 
in  effect  a  special  development  of  the  holder  process.  Milk  heated  to 
about  145°F.  is  filled  into  hot  steamed  bottles  and  is  capped  and  then 
cooled  by  an  air  blast.  The  advantages  claimed  for  the  process  are:  ah 
excellent  bacterial  reduction;  no  liability  to  bottle  infection;  elimination 


THE  MILK  CONTRACTOR  293 

of  loss  from  evaporation  in  passing  over  the  cooler;  and  that  ordinary 
cardboard  caps  may  be  used  to  seal  the  bottles.  The  disadvantages  are 
several.  To  the  cost  of  cooling  the  hot  milk  is  added  that  of  cooling  the 
hot  glass  bottles  and  the  cases  that  hold  them.  One  quart  bottle  weighs 
about  as  much  as  the  milk  it  contains  and  it  has  to  be  cooled  from  145°F. 
to  40°F.  or  lower.  Ayres,  Bowers  and  Johnson  have  recently  published 
the  results  of  their  investigations  on  cooling  hot  bottled  pasteurized  milk 
with  forced  air.  As  there  is  very  little  difference  in  the  relative  rate  of 
cooling  milk  and  water  they  found  it  advisable  to  use  water  in  their 
experiments  but  distributed  bottles  of  milk  throughout  the  crates  for 
temperature  readings  and  for  bacteriological  studies.  They  found  that: 
1.  A  bottle  of  hot  milk  will  cool  about  one-third  faster  in  circulated  than 
in  still  air  and  that  this  is  also  true  of  milk  in  cans  but  that  since  in  cool- 
ing by  this  method  the  time  required  is  chiefly  dependent  on  the  size  of 
the  container,  quart  bottles  are  about  as  large  sized  vessels  as  could  be 
used  in  commercial  practice.  Cooling  hot-bottled  milk  by  natural  cir- 
culation of  air  is  too  slow  for  practical  work.  2.  In  their  experiments, 
which  were  conducted  on  a  basis  of  30  crates  stacked  in  six  piles,  each  five 
crates  high,  it  was  found  that  when  cold  air  was  forced  up  through  the 
crates,  there  was  too  much  variation  in  the  temperature  of  the  same  sized 
bottles  in  different  positions  in  the  stack  and  also  in  that  of  quart  and 
pint  bottles  in  the  same  position  to  admit  of  successfully  cooling  in  this 
way  in  commercial  work.  3.  Better  results  were  obtained  by  reversing 
the  direction  of  the  cooling  air  first  up  and  then  down  through  the  crates 
every  15  min.  during  the  cooling  period  but  this  way  was  not  wholly 
successful.  4.  Satisfactory  results  were  obtained  by  forcing  the  air 
from  the  top  downward.  This  cools  the  milk  in  the  top  of  the  bottles 
first  and  the  cool  milk  being  of  greater  density  settles  to  the  bottom 
and  in  so  doing  forces  the  warmer  lighter -milk  into  its  place.  The  con- 
vectional  currents  that  are  then  established  result  in  there  being  a  dif- 
ference of  only  a  few  degrees  in  temperature  in  the  different  bottles  in 
the  stack  and  in  a  considerably  greater  rate  of  cooling.  When  air  at  40°F. 
was  forced  down  through  the  crates  at  about  2,500  ft.  a  minute  the  bottles 
were  cooled  from  140°F.  to  50°F.  in  2  hr.;  when  the  air  was  at  30°F. 
and  the  rate  1,700  ft.  a  minute  the  bottles  were  cooled  through  the  same 
range  of  temperature  in  1  hr.  and  30  min.;  when  it  was  at  20°F. 
and  was  forced  down  through  at  1,700  ft.  a  minute  the  bottles  were  cooled 
from  140°F.  to  50°F.  in  1  hr.  and  20  min.  5.  The  cost  of  cooling 
by  forced  air  circulation  when  the  outside  air  is  at  40°F.  or  lower,  is 
materially  less  than  that  of  the  usual  methods  of  refrigeration.  6.  Bac- 
teriological studies  indicate  that  if  the  milk  is  cooled  from  145°F.  to  50°F. 
within  5  hrs.  after  pasteurization,  no  more  bacterial  increase  takes  place 
than  when  the  milk  is  cooled  immediately  to  the  same  temperature. 
In  fact,  in  these  experiments  on  a  30-crate  basis,  there  was  marked  re- 


294  CITY  MILK  SUPPLY 

duction  in  the  bacterial  numbers  during  the  cooling  period,  especially 
when  the  raw  milk  contained  large  numbers  of  bacteria  before  pasteuriza- 
tion. As  the  experiments  indicate  that  pasteurized  milk  can  be  cooled 
on  a  commercial  scale  from  145°F.  to  50°F.  by  forced  air  within  3  hr. 
the  process  can  be  completed  well  within  the  5-hr,  limit.  It  is  empha- 
sized that  the  cooling  of  milk  is  absolutely  necessary  and  that  this  proc- 
ess does  not  eliminate  cooling;  it  merely  cools  more  slowly  than  is  at 
present  customary.  7.  So  far  as  could  be  determined  from  experiments 
conducted  on  this  scale,  the  cream  line  and  flavor  of  the  milk  are  not  in- 
jured by  this  process.  8.  These  experiments  indicate  that  it  is  commer- 
cially practicable  to  cool  hot  pasteurized  milk  in  containers  not  larger 
than  quart  bottles  by  forcing  cold  air  downward  over  them,  when  the 
air  is  at  40°F.  or  lower. 

On  account  of  overheating  portions  of  the  milk,  the  process  of  pas- 
teurizing milk  in  bottles  by  forcing  hot  air  over  them  seems  commercially 
impracticable. 

Objections  that  have  been  raised  to  bottling  milk  hot  are  that  the 
air  space  that  is  formed  in  the  bottle  by  the  contraction  of  the  milk  in 
cooling  both  makes  the  package  unattractive  to  the  consumer  and  gives 
opportunity  for  the  milk  to  churn  as  it  is  carried  about  in  the  delivery 
wagons. 

Holders. — Holders  are  of  two  principal  sorts,  namely;  the  absolute  or 
positive  and  the  continuous  holders  or  retarders.  In  the  absolute  hold- 
ers the  heated  milk  is  actually  held  in  insulated  or  jacketed  tanks  or  com- 
partments for  a  definite  period  of  time,  usually  20  to  45  min.  and  at  the 
pasteurizing  temperature.  They  are  very  efficient,  provided  all  the  milk 
is  held  the  full  time,  and  provided  the  temperature  is  maintained.  In 
some  holders  of  this  class  scum  formation  is  excessive  and  impairs  their 
effectiveness  because  the  foam  is  considerably  cooler  than  the  milk  and 
so  the  contained  germs  escape  destruction.  Excessive  foam  formation 
greatly  increases  the  surface  of  the  exposed  milk,  consequently  the  evap- 
oration therefrom  causes  undue  shrinkage  in  the  milk. 

Holders  of  the  absolute  type : 

1.  The  combined  heating,  holding  and  cooling  tanks  described  as 
type  6,  under  heaters. 

2.  A  tank  divided  into  compartments  each  of  which  has  at  the  bottom 
an  outlet  valve  that  is  operated  by  an  arm  connected  to  a  center  shaft 
that  passes  up  through  the  machine  and  makes  one  revolution  in  30  min. 
At  the  top  of  the  shaft  is  a  distributing  trough  that  fills  the  compartments. 
The  emptying  device  is  so  arranged  that  six  of  the  compartments  are  full 
at  a  time,  while  of  the  two  others  one  is  being  emptied  and  the  other 
filled.     In  this  way  a  compartment  after  being  filled  with  hot  milk  is 
held  for  30  min.  after  which  it  is  automatically  emptied.     The  compart- 
ments are  arranged  so  that  when  the  machine  is  going  at  full  capacity 


THE  MILK  CONTRACTOR  295 

they  are  full,  while  at  half  capacity  they  are  half  full,  which  permits  the 
pasteurizing  of  small  batches  of  milk. 

3.  The  holder  consists  of  eight  shallow  pans  arranged  in  two  tiers 
and  supported  in  an  insulated  copper-lined  case  with  enamel  sides.  The 
intake  from  the  heater  discharges  automatically  and  alternately  into  the 
top  pan  of  each  tier,  the  milk  being  held  positively  in  each  pan  one-fourth 
of  the  total  selected  holding  time  and  then  being  automatically  passed 
to  the  pan  below.  It  is  claimed  that  the  passage  of  milk  from  one  pan  to 
another  makes  agitators  to  prevent  separation  of  the  fat  solids  unnecessary. 

Holders  of  the  Continuous  Type. — The  continuous  method  is  less 
satisfactory  than  the  positive;  the  milk  is  retarded  in  its  course  to  the 
cooler  so  that  theoretically  it  is  kept  at  the  pasteurizing  temperature  long 
enough  to  ensure  its  being  thoroughly  pasteurized.  In  reality,  owing 
to  the  unequal  movement  of  different  parts  of  the  milk  stream,  some 
of  the  milk  travels  toward  the  cooler  more  rapidly  than  the  rest  and  so  is 
inadequately  heated.  The  machines  never  work  up  to  their  rated 
efficiency.  There  are  three  general  types  of  retarders: 

1.  This  apparatus  consists  of  an  upright  cylindrical  tank  or  of  two  or 
more  such  tanks  arranged  in  series.     The  milk  is  fed  in  at  the  top  and 
passes  out  at  the  bottom  into  another  tank  or  if  a  single  tank  is  used  the 
outlet  pipe  is  carried  up  nearly  to  the  top  of  the  tank  and  downward  again 
to  the  cooler,  thus  permitting  no  milk  to  discharge  from  the  tank  till  the 
milk  therein  reaches  the  level  of  the  top  of  the  outlet  pipe.     Single  tanks 
are  unsatisfactory  for  the  milk  tends  to  stratify  with  the  hot  milk  at  the 
top,  consequently  the  milk  in  different  parts  of  the  tank  is  held  unequally. 
Holders  of  this  type  are  difficult  to  clean  and  are  said  to  have  a  holding 
efficiency  of  but  25  to  50  per  cent,  of  their  theoretical  capacity. 

2.  Holders  of  this  sort  are  horizontal  tanks  with  cross-partitions  or 
baffles  to  impede  the  flow  of  milk  through  the  tank  from  one  end  to  the 
other.     The  best  show  an  efficiency  of  from  10  to  15  per  cent,  of  their 
theoretical  capacity. 

3.  Machines  of  this  type  are  horizontal  tubular  holders  in  which 
the  milk  enters  the  topmost  of  a  series  or  bank  of  tubes  and  passes  back- 
ward and  forward  through  them  all,  till  it  emerges  from  the  bottom  tube. 
Tubular  holders  have  an  efficiency  of  from  80  to  85  per  cent,  of  their 
theoretical  capacity.     As  in  the  case  of  the  tubular  heaters,  it  is  difficult, 
owing  to  the  slight  inclination  of  the  tubes,  to  remove  the  last  milk  at  the 
end  of  the  run.     Pains  must  be  taken  to  clean  the  tubes  thoroughly. 
Heaters  of  every  type  must  be  warmed  with  steam  before  running  milk 
through  them,  otherwise  the  first  milk  to  pass  is  apt  to  be  cooled  below  the 
pasteurizing  temperature  with  the  result  that  the  bacteria  it  contains  are 
not  killed. 

Regenerative  Pasteurizers. — The  object  of  regenerative  pasteurizers 
is  to  economize  heat  and  ice.  This  is  effected  by  utilizing  the  hot  milk 


296 


CITY  MILK  SUPPLY 


from  the  heater  or  holder  to  heat  the  cold  raw  milk  on  its  way  to  the  heater. 
There  are  several  ways  of  arranging  the  apparatus  to  do  this;  the 
heating  of  the  cold  milk  may  take  place  within  the  heater  or  in  the  cooler. 
If  it  is  done  within  the  heater  the  pasteurized  hot  milk  in  the  course  of  its 
passage  to  the  cooler  through  the  machine  is  forced  over  a  surface  against 
the  other  side  of  which  the  incoming  cold  flows.  So  the  hot  milk  gives 
up  heat  to  the  cold  milk.  In  case  a  holder  is  used  with  such  machines 
the  hot  milk  from  it  is  returned  to  the  heater  and  following  the  usual 
course  to  the  cooler  heats  the  raw  milk  on  the  way.  Where  the  regenera- 


Courtesy  of  Robert  Burnett. 

FIG.  42. — Pasteurizing  milk  in  the  bottle  at  Deerfoot  Farms,  Southboro,  Mass. 

tion  is  accomplished  in  the  cooler,  the  pasteurized  hot  milk  passes  from 
either  the  heater  or  holder  to  the  cooler  and  flowing  down  on  the  outside 
of  the  cooler  warms  the  cold  milk  which  in  some  types  of  coolers  passes 
through  the  inside  of  the  cooler  and  in  others  runs  down  one  side  of  the 
cooler  while  the  hot  milk  runs  down  the  other.  By  the  regenerative 
process  the  temperature 'of  the  cold  raw  milk  on  its  way  to  the  cooler  is 
raised  through  40°F.  or  more  while  the  hot  milk  that  is  passing  over  the 
cooler  is  chilled  a  like  amount;  thus  a  saving  of  both  steam  and  ice  is 
effected. 

The  invention  of  the  Dacro  metal  cap  by  William  Painter  in  1892  an 


THE  MILK  CONTRACTOR  297 

the  putting  on  the  market,  in  1910,  of  a  size  thereof  especially  adapted  to 
milk  bottles  made  it  possible  to  submerge  the  bottles  for  pasteurization 
and  led  to  the  adoption  of  pasteurization  in  the  final  package  on  a  com- 
mercial scale.  Since  that  time  other  caps  adopted  to  this  sort  of  pas- 
teurization have  appeared.  One  of  the  first  to  adopt  the  bottle  process 
was  Robert  Burnett  who  has  used  it  under  the  direction  of  Prescott  at  his 
Deerfoot  Farm  in  Southboro,  Mass.,  since  Aug.  1,  1911.  D.  Whiting  & 
Sons,  also  of  Boston,  under  the  direction  of  Stedman  Bixby  have  pas- 
teurized a  part  of  their  supply  by  this  method  since  September,  1911. 

In  practical  work  the  bottles  are  filled  with  milk  to  a  level  that  leaves 
about  2  per  cent,  of  their  total  capacity  as  an  air  space.  They  are  then 
capped  and  heated  in  water  that  has  a  temperature  of  about  150°F.  for  a 
period  of  30  min.  from  the  time  the  milk  reaches  145°F.  They  are  then 
gradually  cooled  and  are  finally  put  in  cold  storage.  Commercial  houses 
have  long  had  data  as  to  the  efficiency  of  the  method  but  Ayres  and  John- 
son and  also  Hammer  are  the  first  to  publish  results  of  careful  studies  of 
the  process. 

The  two  former  authors  find  that  pasteurization  in  the  bottle  at  145°F. 
for  30  min.  gives  satisfactory  bacterial  reductions.  They  advise  that  in 
order  to  destroy  heat-resisting  organisms,  which  may  survive  the  pasteuriz- 
ing temperature,  the  bottles  be  steamed  for  at  least  2  min.  before  being 
filled  with  milk.  They  observe  that  during  the  period  the  milk  is  being 
heated  the  temperature  varies  markedly  in  different  parts  of  the  bottle. 
If  milk  at  50°F.  is  heated  in  bottles  without  agitation,  in  water  at  146°F., 
the  temperature  at  the  top  of  the  bottle  will  reach  140CF.  about  9  min. 
before  that  in  the  bottom  does.  In  actual  pasteurization  the  bulb  of  the 
thermometer  should  be  placed  about  J^  in.  from  the  bottom  of  the  con- 
trol bottle.  If  bottles  with  chipped  or  otherwise  imperfect  tops  are  used, 
serious  contamination  of  the  milk  may  result  from  leakage  of  the  water 
into  the  milk. 

Hammer's  results  are  in  general  accord  with  those  of  Ayres  and  John- 
son, but  he  advises  an  exposure  of  50  min.  in  water  at  145°F.  for  milk  in 
half  pint,  pint  and  quart  bottles  and,  basing  his  opinion  on  experiments 
with  pint  bottles,  concludes  that  this  exposure  would  be  satisfactory  also 
for  cream.  Milk  pasteurized  at  145°F.  for  50  min.  soured  slowly  with  a 
typical  lactic  acid  curd  and  without  gas  formation.  As  the  vat  tempera- 
ture was  increased  above  145°F.,  the  results  were  progressively  undesirable 
until  at  temperatures  between  160°  and  170°F.,  the  cream  line  was  inter- 
fered with  and  a  cooked  flavor  imparted  to  the  milk.  The  flavor  of  the 
milk,  pasteurized  as  recommended,  was  acceptable  to  most  people.  Unde- 
sirable flavors  in  the  raw  milk  were  not  decreased  by  this  method  of  pas- 
teurization and  sometimes  they  were  intensified.  In  some  cases  a  flavor 
was  imparted  to  the  milk  by  the  paper  lining  of  the  cap  and  to  remedy  this 
the  manufacturers  made  a  cap  with  a  parchment  paper  lining.  Instances 


298  CITY  MILK  SUPPLY 

occurred  of  a  cream,  with  a  trifle  higher  acidity  than  usual,  giving  on 
pasteurization  a  thin  layer  of  free  fat  and  imparting  a  granular  feel  to  the 
tongue. 

Bottling  Milk  Hot. — With  regard  to  bottling  milk  hot  Ayres  and 
Johnson  concluded  that  as  good  or  even  better  bacterial  reductions  can  be 
obtained  than  when  the  milk  is  pasteurized  in  the  bottle.  Bottle  infec- 
tion is  eliminated,  even  when  several  cubic  centimeters  of  old  sour  milk  are 
added  to  the  bottles  before  filling  them.  The  2-min.  steaming  that 
bottles  receive  before  being  filled  with  hot  milk  destroys  the  contamina- 
tion. Laboratory  experiments  indicate  that  milk  may  be  pasteurized, 
bottled  hot,  capped  with  ordinary  cardboard  caps  and  cooled  with  a  cold 
air  blast.  It  is  probable  that  if  milk  is  cooled  from  145°F.  to  50°F.  within 
5  hr.  no  greater  bacterial  increase  will  take  place  than  if  it  is  cooled  at  once 
to  50°F.  Future  experiments  will  be  necessary  to  determine  whether 
this  will  be  true  under  commercial  conditions.  So  far  as  laboratory  ex- 
periments show,  milk  that  is  heated  to  145°F.  for  30  min.  and  bottled  hot, 
when  subjected  to  slow  gradual  cooling  through  periods  of  less  than  5  hr. 
duration,  is  liable  to  no  more  trouble  with  the  cream  line  and  with  off 
flavors  than  is  milk  pasteurized  and  cooled  in  the  usual  way.  A  quart  of 
milk  in  cooling  from  145°  to  50°F.  shrinks  about  0.62  oz.;  so  slightly 
oversized  bottles  should  be  used  for  bottling  milk  hot. 

Difficulties  Encountered  in  Pasteurization. — In  commercial  pasteur- 
ization difficulties  of  different  sorts  are  encountered.  Milk  occasionally 
coagulates  in  the  pasteurizing  apparatus.  Harding  and  Rogers  state 
that  it  has  been  found  impractical  to  pasteurize  milk  intended  for  im- 
mediate consumption  when  the  acidity  is  over  0.2  per  cent,  calculated  as 
lactic  acid,  and  in  the  course  of  their  experiments  on  the  efficiency  of  a 
continuous  pasteurizer,  having  a  steam-heated  jacket,  they  found  that  as 
the  acidity  approached  0.36  per  cent,  a  considerable  layer  burned  fast 
to  the  sides  of  the  milk  chamber  of  the  pasteurizer  and  the  accumulation 
in  the  separator  bowl  was  increased.  The  question  was  studied  by  Kastle 
who  concluded  from  his  own  results  and  those  of  others  that  the  coagu- 
lation of  milk  is  dependent  on  several  factors  among  which  are:  time, 
temperature,  degree  of  acidity,  quantity  and  nature  of  the  calcium  salts, 
etc.;  and  that  in  order  to  avoid  accidents  resulting  from  curdling  in  the 
pasteurization  of  milk,  the  only  safe  rule  to  follow  is  to  determine  the 
effect  of  heat  on  small  samples  of  milk  which  it  is  proposed  to  pasteurize. 

A  cooked  flavor  is  noticed  by  many  consumers  in  milk  heated  to  158°F. 
It  is  probably  due  to  the  effect  of  heat  on  the  milk  sugar  and  may  be 
avoided  by  the  use  of  low  temperatures  in  pasteurization. 

Much  trouble  has  been  experienced  from  the  fact  that  pasteurized 
milk  may  have  an  ill-defined  cream  line  and  may  show  shrinkage  in  the 
volume  of  cream  that  rises  to  the  top  of  the  container.  The  accepted 
explanation  of  this  fact  has  been  that  in  raw  milk  the  fat  is  in  clusters 


THE  MILK  CONTRACTOR  299 

which,  being  lighter  than  the  serum  of  the  milk  and  having  a  relatively 
small  surface  in  proportion  to  their  cubic  content,  readily  rise  to  the 
surface  to  form  cream,  whereas  in  the  heated  milk  the  clusters  are  dis- 
rupted and  the  single  globules  fail  to  rise  to  the  surface  because  they  have 
relatively  large  surfaces  which  meet  enough  resistance  to  offset  the  force 
of  gravity  that  tends  to  make  them  rise.  Recently,  Peter  of  the  Swiss 
Dairy  School  in  Berne  has  shown  that  the  rapidity  of  the  formation  as 
well  as  the  depth  of  the  cream  line  increases  up  to  a  pasteurizing  tempera- 
ture of  141. 8°F.  beyond  which  it  decreases,  but  even  at  145.4°F.  was 
greater  than  in  raw  milk.  So  the  usual  explanation  cannot  be  accepted; 
instead  it  is  held  that  heating  decreases  the  viscosity  of  milk  and  so  facili- 
tates the  rising  of  the  fat  globules  but  that  at  temperatures  above  145.4°F. 
an  abundant  though  invisible  coagulation  of  the  albumen  retards  or  pre- 
vents the  rising  of  the  fat  globules.  Kilborune  investigated  the  question 
and  found  that  when  milk  is  cleaned  by  the  centrifugal  clarifier  the  vol- 
ume of  the  cream  in  the  milk  is  reduced  2  to  3  per  cent.  He  found,  too, 
that  the  volume  of  cream  in  bottled  milk  is  affected  by  several  imper- 
fectly understood  factors,  viz. : 

1.  The  temperature  to  which  the  milk  is  heated. 

2.  The  length  of  time  at  which  the  milk  is  held  at  high  temperature. 

3.  The  temperature  of  the  heating  medium  with  which  the  milk  comes  into  contact 
during  the  heating  process. 

4.  The  clarification  of  the  milk. 

5.  The  amount  of  agitation  to  which  the  milk  is  subjected  especially  while  hot. 
This  is  an  important  factor.     It  was  noted  that  in  those  plants  where  there  was  most 
agitation  of  the  milk  and  particularly  when  pumping  of  the  hot  milk  was  practised,  the 
most  difficulty  with  the  cream  line  was  experienced. 

Other  factors  that  he  believed  might  possibly  affect  the  cream  line  are : 

1.  The  age  of  the  milk  at  pasteurization. 

2.  The  grade  of  the  cows  that  produced  the  milk. 

3.  Whether  or  not  the  milk  had  been  frozen  before  pasteurization. 

As  a  result  of  these  studies  the  New  York  City  Board  of  Health  now 
requires  that  for  milk  to  be  considered  pasteurized  it  must  have  been 
exposed  to  temperatures  between  142°F.  and  145°F.  for  not  less  than  30 
min. 

There  is  some  evidence  that  the  method  of  cooling  the  milk  effects 
the  volume  and  character  of  the  cream.  There  are  experiments  which 
indicate  that  in  vat  pasteurization,  if  the  milk  is  cooled  in  the  vats,  a 
slow  process,  the  cream  line  is  not  very  distinct,  whereas  if  the  milk  is 
cooled  quickly  by  running  it  out  of  the  tanks  over  coolers  the  cream  line 
is  sharply  defined  and  the  cream  on  analysis  shows  more  casein  than 
does  the  slowly  cooled  cream. 

Excessive  loss  from  evaporation  is  to  be  guarded  against  in  pasteur- 
ization. For  that  reason  the  heated  milk  should  not  be  exposed  to  the 


300  CITY  MILK  SUPPLY 

air.  Probably  the  greatest  loss  occurs  when  pasteurizing  is  done  in  open 
vats  or  the  cooling  is  done  over  an  open  cooler.  To  prevent  loss  from 
the  latter  source  many  firms  use  an  internal  cooler  of  the  type  that  has 
one  set  of  tubes  enclosed  within  another.  Usually  such  coolers  are  re- 
generative, the  incoming  cold  milk  being  used  to  cool  the  outgoing 
pasteurized  milk  and  being  itself  heated  in  the  process.  It  is  impossible 
to  state  the  loss  that  occurs  from  evaporation  because  it  varies  so  much 
in  different  plants.  In  some  it  amounts  to  as  much  as  4  per  cent,  of  the 
milk  pasteurized  but  this  is  excessive ;  with  careful  management  it  should 
be  kept  under  1  per  cent. 

Besides  the  loss  of  milk  that  evaporation  causes,  there  is  that  which 
arises  from  spilling  the  milk  in  passing  it  through  the  pasteurizing  machin- 
ery and  from  that  which  is  left  behind  in  the  machine.  This,  too,  varies 
greatly  in  amount,  being  little  in  some  plants  and  large  in  others  accord- 
ing to  the  care  and  types  of  machines  used. 

The  tendency  of  the  treated  milk  to  froth  or  foam  causes  considerable 
trouble  because  it  makes  the  milk  difficult  to  handle,  because  it  tends 
to  produce  excessive  evaporation,  and  because  the  foam  is  likely  to  be 
several  degrees  cooler  than  the  body  of  the  milk  in  the  holder  and  so  to 
cause  imperfect  pasteurization.  The  trouble  has  been  overcome  to  some 
extent  by  filling  the  holders  from  the  bottom. 

Milk  should  never  be  pumped  after  it  is  pasteurized  because  it  is 
likely  to  be  recontaminated  and  because,  if  the  pumping  is  done  while 
the  milk  is  hot,  the  volume  of  the  cream  that  will  rise  on  it  is  greatly 
reduced. 

At  certain  seasons  of  the  year  there  is  a  tendency  for  the  cream  of 
pasteurized  milk  to  form  a  tough  leathery  layer  on  top  of  the  milk.  This 
is  believed  to  be  due  to  needlessly  rough  handling  in  the  course  of  pasteur- 
ization and  to  occur  at  those  seasons  when  atmospheric  temperatures 
approach  those  of  churning,  about  62°F. 

Importance  of  Temperature  Control. — The  vital  part  of  pasteuriza- 
tion is  the  use  of  the  proper  degree  of  heat;  hence  temperature  control  is 
of  the  utmost  importance.  Skill  and  care  are  required  to  successfully 
operate  a  pasteurizer.  In  the  first  place  in  starting  a  machine  the  tempera- 
ture rises  gradually  and  the  apparatus  as  a  whole  is  not  promptly  heated 
to  the  required  temperature  so  that  the  first  milk  to  pass  is  apt  to  be  under- 
pasteurized.  Therefore,  it  is  customary  to  run  it  through  the  machine  a 
second  time;  when  this  is  done  the  milk  should  not  be  allowed  to  pass  over 
and  contaminate  the  cooler  before  being  returned  to  the  heater.  In  some 
plants  hot  water  is  run  through  the  apparatus  to  heat  up  and  sterilize 
the  apparatus.  This  procedure  is  excellent  but  care  must  be  taken  to 
remove  all  of  the  hot  water  before  actual  pasteurization  is  begun.  Again, 
in  starting  it  takes  some  machines  time  to  settle  down  to  the  maintenance 
of  even  temperatures  and  until  they  have  done  so  the  milk  they  are  han- 


THE  MILK  CONTRACTOR  301 

dling  is  likely  to  be  imperfectly  pasteurized.  After  the  machine  is  started 
and  running  well  interruptions  from  non-arrival  of  the  milk  at  the  plant, 
breakdown  of  the  machinery,  neglect  to  keep  up  steam  pressure,  and  other 
accidents  may  cause  failure.  Besides,  if  the  work  is  late  or  there  is  an 
extra  amount  of  milk  to  be  pasteurized,  the  machine  may  be  crowded  at 
the  expense  of  efficiency.  Also,  since  overheated  milk  is  almost  certain 
to  cause  complaint  from  customers,  there  is  the  constant  temptation  to 
pasteurize  close  to  the  lower  temperature  limit  which  means  that  the 
heating  it  is  apt  to  be  insufficient  to  kill  the  pathogenic  germs.  So,  it  is 
imperative  that  every  pasteurizing  plant  shall  employ  efficient  methods  of 
controlling  the  temperature  and  of  recording  that  actually  used  during 
the  entire  run. 

Ayres  states  that  a  competent  man  in  a  small  plant  by  hand  control 
can  regulate  the  pasteurizing  temperature  within  2°  or  3°  each  way  but 
that  in  large  plants  mechanical  control  is  much  more  certain  for  there 
are  numerous  controllers  that  will  run  within  1°  each  way,  of  the  desired 
temperature.     The  underlying  principle  of  automatic  control  is  the  regu- 
lation of  the  steam  flow  by  a  diaphragm  valve,  operated  by  air  pressure, 
regulated  by  expansion  and  contraction  in  the  controller  bulb  which  is 
placed  in  the  milk  outlet  of  the  pasteurizer.     By  setting  the  controller 
any  desired  temperature  may  be  obtained.     The  bulb  of  the  recording 
thermometer  is  inserted  in  the  milk  as  it  leaves  the  pasteurizer  and  regis- 
ters on  a  chart  a  continuous  record  of  the  temperature  maintained  during 
the  run.     Care  should  be  exercised  that  the  controller  and  recorder  bulbs 
are  affected  only  by  the  temperature  of  the  milk  for  if  they  are  exposed 
to  warm  surfaces,  or  escaping  steam  or  if  they  are  placed  where  the  cir- 
culation of  the  milk  is  sluggish,  erroneous  results  will  be  obtained.     The 
U.  S.  Department  of  Agriculture  states  that  relatively  few  plants  are 
using  automatic  temperature  controllers  and  urges  their  adoption,  saying 
that  the  power  used  in  operating  them  is  not  greater  than  the  steam  wasted, 
where  hand  control  is  used  and  estimating  the  daily  overhead  expense  of 
the  instruments  at  11  cts.,  or  less  than  the  wage  of  one  man  for  an  hour. 
The  temperature  chart  not  only  shows  the  temperature  used  at  any  period 
of  the  process  but  in  all  holder  systems,  except  those  using  retarders, 
shows  the  period  of  time  through  which  any  temperature  was  maintained. 
Thus  these  charts  are  valuable  evidence  as  to  the  efficiency  with  which 
the  pasteurization  is  conducted.     So,  boards  of  health  in  some  principal 
cities  of  the  United  Stated  require  the  use  of  continuous  temperature 
recorders  and  it  would  seem  wise  for  other  cities  to  follow  their  lead,  for 
such  records  are  the  best  possible  guarantee  that  pasteurization  is  being 
properly  done.     The  validity  of  the  Chicago  ordinance  which  requires 
the  use  of  continuous  temperature  recorders  has  been  upheld  by  the  courts 
in  Koy  vs.  the  City  of  Chicago  et  al.,  111.,  104,  N.  E.  R.,  1,104. 


302  CITY  MILK  SUPPLY 

Actual  Pasteurization. — In  actual  pasteurization  the  first  thing  is  for 
the  operator  to  assure  himself  that  the  apparatus  is  in  condition  to  start 
the  run.  It  is  assumed  that  the  apparatus  is  so  placed  that  the  milk  in 
the  course  of  its  passage  is  not  unnecessarily  exposed  to  dust  and  that  at 
the  close  of  work  on  the  preceding  day  the  whole  outfit  was  thoroughly 
scrubbed  and  rinsed.  So  the  inspection  preliminary  to  starting  the  run 
should  be  a  close  one  in  which  the  effort  is  to  make  sure  that  the  apparatus 
is  set  up  properly  and  is  mechanically  sound  that  the  run  may  proceed  with- 
out interruption  and  to  detect  any  dirt  that  may  lurk  in  seams,  turns  and 
corners.  Then,  because  dust  has  settled  on  the  machinery  since  it  was 
scrubbed,  every  piece  is  given  a  final  cleansing.  The  receiving  tanks  are 
rinsed  with  hot  water  and  blown  out  with  steam.  The  separator  and 
clarifier  are  rinsed  with  hot  water.  If  a  strainer  is  used,  pains  are  taken 
to  see  that  it  is  in  fit  condition.  Wire  strainers  are  apt  to  collect  cheesy 
material  between  the  meshes,  quartz  filters  must  be  carefully  washed 
and  sterilized  with  steam,  and  cloth  filters  must  be  renewed  after  each 
run  and  must  be  put  together  carefully.  Both  the  heater  and  holder 
are  rinsed  off  with  hot  water.'  Dust  that  has  settled  on  the  cooler  is 
rinsed  off  with  hot  water  and  the  cooler  afterward  steamed.  The 
apparatus  is  then  ready  for  use;  the  milk  is  started  through  and  the  proc- 
ess conducted  in  accordance  with  the  procedure  approved  for  the 
machinery  in  use.  The  results  should  be  satisfactory  but  if  they  are  not, 
samples  for  bacterial  test  must  be  taken  of  the  milk  as  it  enters  and  as  it 
issues  from  each  machine  that  composes  thep  asteurizing  unit,  for  only 
in  this  way  can  the  part  that  is  doing  faulty  work  be  located. 

Efficiency  of  Pasteurization. — The  efficiency  of  pasteurization  is 
commonly  judged  by  the  reduction  that  is  affected  in  the  bacterial  con- 
tent of  the  raw  milk.  This  is  stated  either  by  giving  the  numbers  of  bac- 
teria in  both  the  raw  and  the  pasteurized  milk,  as  for  example  10,000,000 
per  cubic  centimeter  before  and  200,000  after  pasteurization,  or  by  giving 
the  percentage  of  reduction  accomplished,  which  is  sometimes  called  the 
"bacterial  efficiency,"  as  for  instance  98  per  cent.  This  is  sometimes  mis- 
leading, in  this  way;  a  bacterial  efficiency  of  98  per  cent,  on  a  milk  that 
contained  10,000,000  bacteria  per  cubic  centimeter  would  mean  that  there 
would  remain  in  the  milk  200,000  bacteria  per  cubic  centimeter  whereas 
with  the  same  efficiency  on  a  milk  that  contained  105000  bacteria  per 
cubic  centimeter,  but  200  bacteria  per  cubic  centimeter  survived.  Ayres 
and  Johnson  show  that  the  percentage  of  bacterial  reduction  has  no  special 
meaning  since  it  is  influenced  by  the  numbers  and  kinds  of  bacteria  in  the 
milk  pasteurized.  As  a  general  rule,  when  there  are  many  bacteria  in 
the  raw  milk  there  will  be  a  high,  and  when  there  are  few  there  will  be  a 
low,  percentage  reduction.  While  the  bacterial  count  is  a  good  index 
of  efficiency,  it  is  open  to  criticism  on  the  ground  that.it  makes  the  assump- 
tion that  a  high  reduction  in  the  count  shows  the  destruction  of  pathogenic 


THE  MILK  CONTRACTOR 


303 


bacteria.  Since  the  disease-producing  organisms  and  viruses  that  are 
commonly  carried  in  milk  have  thermal  death  points  below  the  tempera- 
ture of  pasteurization,  the  assumption  is  generally  correct  but  it  is  entirely 
possible  that  heaters  that  heat  the  milk  unequally,  or  holders  that  do 
not  hold  all  of  the  milk  the  full  period,  or  retarders  that  permit  the  passage 
of  portions  of  the  milk  more  rapidly  than  others,  or  slack  operation  of  the 
plant  might  show  bacterial  reductions  and  yet  there  might  be  failure  to 
kill  all  pathogenic  bacteria.  Low  bacterial  counts  backed  by  tempera- 
ture record  cards  and  by  faithful  inspection  are  a  safer  guarantee  of 
efficiency  than  the  counts  alone.  It  may  seem  to  some  that  the  logical 
way  to  test  the  efficiency  of  pasteurization  would  be  to  look  for  disease 
germs  in  the  pasteurized  milk  and  so  it  would  be,  if  bacteriological  tech- 
nique was  developed  to  the  point  where  this  could  be  quickly  and  cer- 
tainly done,  but  it  is  not. 

Method  of  Cooling. — After  pasteurization  milk  must  be  cooled.  It 
was  formerly  held  that  sudden  cooling  was  essential  for  it  was  believed 
that  it  helped  to  destroy  the  bacteria.  Ayres  and  Johnson  made  some 
experiments — Table  84 — which  show  that  this  is  not  so.  The  value  of 
the  sudden  cooling  lies  in  this;  that  after  pasteurization  the  milk  is  pre- 
vented from  slowly  cooling  through  temperatures  around  100°F.  where 
bacterial  multiplication  is  sure  to  be  rapid. 

TABLE  84. — EFFECT  OF  SUDDEN  COOLING  ON  THE  BACTERIAL  CONTENT  OF  PASTEUR- 
IZED MILK  (AYRES  AND  JOHNSON) 


Bacteria 

Pasteurized  at 

145°F.,  30  min. 

Bacteria  per 

Pasteurized  at 

160°F.,  30  min. 

Sam- 
S'o6 

» 

per  cubic 
centimeterj 
in  raw  milk 

Bacteria  per 
cubic  centi- 
meter in  milk 
not  cooled 

Bacteria  per 
cubic  centi- 
meter in  cooled 
milk 

pie 
No. 

cubic  centi- 
meter in 
raw  milk 

Bacteria  per 
cubic  centi- 
meter in  milk 
not  cooled 

Bacteria  per 
cubic  centi- 
meter in  cooled 
milk 

1 

2 

186,000 
233,000 

8,600 
1,470 

8,500 
2,160 

3 

4 

400,000 
1,350,000 

1,880 

1,750 

1,950 
1,700 

Later  these  authors  studied  the  question  of  how  quickly  milk  must  be 
cooled  in  order  to  check  bacterial  growth  and  in  the  course  of  their  inves- 
tigation made  three  experiments  to  show  respectively  the  effect  on  the 
bacterial  content  of  cooling  quickly,  slowly  and  not  cooling  at  all.  Milk 
was  pasteurized  in  bulk  and  the  hot  milk  filled  into  three  steamed  hot 
quart  bottles.  One  bottle  was  cooled  in  ice  water  in  %  nr-  to  50°F.  and 
refrigerated  at  45°F.  Another  was  cooled  in  a  blast  of  air  at  room 
temperature  for  J^  hr.  during  which  time  the  temperature  of  the  milk 
dropped  from  about  145°F.  to  80°F.  in  5  hr.  after  which  it  was  placed  in  a 
refrigerator  at  45°F.,  where  it  cooled  slowly  in  still  air.  The  third  bottle 
was  cooled  for  J^  hr.  in  an  air  blast  at  room  temperature  and  held 
at  about  75°F.  throughout  the  experiment.  The  results  are  given  in 
Table  85. 


304 


CITY  MILK  SUPPLY 


TABLE  85. — EFFECT  OF  DIFFERENT  METHODS  OF  COOLING  ON  THE  BACTERIAL  CON- 
TENT OF  PASTEURIZED  MILK  (AYRES  AND  JOHNSON) 


Method  of  cooling 

Sample  No. 

1 

2 

Bacteria  per  cu 

3 
bic  centimeter 

Raw  milk                              

9,050,000 

6,450 
5,050 
4,800 
1,370,000 

7,150 
6,100 
6,200 
9,600 
2,760,000 

4,950 
6,850 
700,000 
2,750,000 
460,800,000 

11,900,000 

9,500 
28.400 
76^500 

Bottle  No.  1  cooled  quickly 
Directly  after  pasteurization 

2,110 
1,720 
2,340 
885,000 

2,580 
1,600 
2,400 
2,740 
850,000 

2,180 
2,890 
2,420,000 
13,400,000 

Held  at  45°F.  for  22  hr.  
Held  at  75°F  for  6  hr. 

Held  at  75°F  for  24  hr 

Bottle  No.  2  cooled  slowly 
Directly  after  pasteurization            

11,900 
29,000 
192,000 
348,000 

8,500 
25,000 
83,400,000 
269,000,000 

Held  at  75  °F  for  5  hr 

Held  at  45°F.  for  17  hr  

Held  at  75°F  for  6  hr                    

Held  at  75°F  for  24  hr 

Bottle  No.  3  cooled  at  room  temperature 
Directly  after  pasteurization           

Held  at  75°F  for  5  hr 

Held  at  75°F.  f  or  22  hr  
Held  at  75°F  for  28  hr                       

Held  at  75°F.  for  66  hr.  .  . 

The  table  shows  no  increased  bacterial  growth  in  samples  1  and  2 
from  holding  the  pasteurized  milk  5  hr.  after  bottling  hot,  even  though 
the  temperature  ranged  between  80°  and  100°F.  which  limits  comprise  the 
temperatures  most  favorable  for  bacterial  development.  In  sample  3  the 
milk  that  was  cooled  slowly  does  show  an  increased  growth  over  that  which 
was  cooled  rapidly,  but  even  so  it  is  to  be  remembered  that  the  experiments 
represent  extreme  conditions  in  slow  cooling  and  so  it  would  seem  proper 
to  infer  from  the  three  samples  that  the  cooling  process  can  be  delayed 
but  that  it  should  not  extend  over  5  hr.  The  writers  make  application 
of  this  in  their  process  of  cooling  with  an  air  blast,  milk  bottled  hot. 
They  strongly  emphasize  the  fact  that  the  table  shows  that  milk  not  cooled 
to  low  temperatures  soon  has  a  higher  bacterial  count  than  either  milk 
cooled  slowly  or  that  cooled  rapidly,  which  should  drive  home  the  practical 
point  that  milk  must  be  cooled  to  low  temperatures  after  pasteurization. 

Inspection  of  Pasteurizing  Plants. — The  inspection  of  pasteurizing 
plants  by  those  in  official  position  should  be  done  in  a  systematic  and 
thorough  manner.  The  description  by  Sturgis  of  the  way  it  is  done  by 
the  Department  of  Health  of  New  York  City  gives  a  clear  idea  of  how 
such  work  should  be  conducted. 

"The  complete  inspection  of  a  pasteurizing  plant  involves  the  examination 
before,  during  and  after  the  operation,  in  order  to  note  the  condition  of  the  ap- 
paratus and  the  care  given  to  its  cleanliness  at  all  times,  as  well  as  to  watch  the 


THE  MILK  CONTRACTOR  305 

actual  handling  of  milk.  The  inspector,  therefore,  first  carefully  examines  all 
pipes  and  connections,  pumps  and  other  apparatus  used  in  handling  the  milk, 
taking  the  various  fittings  apart,  if  necessary,  to  assure  himself  of  their  cleanliness. 
He  also  watches  the  sterilizing  of  pipes  and  vats  before  their  use,  which  process 
serves  also  to  enable  the  first  milk  to  hold  its  temperature  without  undue  loss. 
During  the  actual  handling  of  milk  the  inspector  notes  its  condition  upon  receipt 
as  to  dirt,  temperature,  sweetness,  etc.,  and  watches  to  see  that  it  is  not  exposed 
to  dust  or  dirt.  The  temperature  during  its  pasteurization  is  recorded  automat- 
ically upon  the  dial  of  a  clock  recorder,  the  accuracy  of  which  is  tested  at  each 
inspection.  These  recording  devices  will  also  indicate  the  holding  period  in 
certain  forms  of  absolute  holders,  but  will  not  perform  this  function  in  the  case  of 
continuous  retarders.  In  this  latter  type  of  apparatus  the  holding  period  is 
best  ascertained  by  watching  the  speed  at  which  the  milk  is  dumped  through 
them.  Upon  leaving  the  holders  the  milk  must  be  cooled  quickly  to  a  low  tem- 
perature, preferably  from  40°  to  45°F.  or  even  lower  and  then  immediately  placed 
in  the  cans  or  bottles  in  which  it  is  to  be  shipped.  The  inspector  notes  the  tem- 
perature of  cooling  at  frequent  intervals,  and  is  thereby  enabled  to  advise  if  the 
hot  milk  is  fed  to  the  cooler  too  fast  to  obtain  good  results,  and  have  the  flow 
regulated  in  accordance.  The  cleanliness  of  bottles  and  cans  used  for  holding 
pasteurized  milk  is  a  feature  of  great  importance.  The  aim  of  the  department 
is  to  obtain  sterility  of  containers  after  they  have  been  cleaned,  and  here  the 
personal  effort  of  the  inspector  can  often  accomplish  better  results  than  any  pre- 
scribed set  of  regulations.  Bacteriological  examinations  of  rinsings  with  a  sterile 
water  control  is  the  guide  that  is  followed,  and  inspectors  are  kept  closely  in- 
formed of  all  such  results.  The  commonly  accepted  standard  in  such  cases  is  a 
count  of  1,000  for  bottles  and  of  40,000  for  cans,  50  c.c.  of  sterile  water  being  used. 

"After  pasteurization  for  the  day  is  concluded  attention  is  directed  first  to 
the  correct  labeling  of  the  milk  and  its  refrigeration  pending  shipment,  and  then 
the  important  feature  of  thoroughly  cleaning  the  apparatus.  First  of  all  the 
pipes  and  pumps  must  be  taken  apart  and  each  length  or  piece  washed,  scrubbed 
and  rinsed.  A  plentiful  supply  of  hot  water  and  a  liberal  use  of  it  is  essential. 
Then  after  the  apparatus  is  assembled  again  it  "must  be  sterilized  by  live  steam 
for  at  least  half  an  hour.  After  this  is  done  empty  cans  and  bottles  returned  from 
the  city  are  washed,  rinsed  and  steamed  in  order  to  be  ready  for  the  following 
day. 

"The  schedules  of  inspection  are  arranged  so  as  to  provide  that  samples  of 
the  milk  are  taken  during  inspection  of  pasteurizing  plants  at  stated  intervals. 
Four  samples  are  taken  at  each  of  the  various  steps  and  from  these  four  individ- 
ual samples  an  average  is  obtained  which  fairly  reflects  the  quality  of  the  milk 
and  also  serves  as  a  check  upon  the  thoroughness  of  pasteurization.  Usually 
these  samples  are  taken  from  (a)  the  raw  milk,  (6)  at  the  outlet  of  the  holder  or 
after  the  milk  has  been  heated  and  held,  (c)  from  the  outlet  of  the  cooler,  (d) 
from  bottles  or  cans  that  have  been  filled  for  shipment.  These  samples  are 
thoroughly  chilled,  packed  in  ice,  and  shipped  in  the  milk  car  to  the  city  terminal 
where  they  are  collected  upon  arrival  and  taken  to  the  laboratory. 

"There  are  so  few  occasions  during  inspections  of  pasteurizing  plants  that 
fail  to  show  some  defect,  serious  or  trivial,  in  equipment  or  operation,  and  the 
conjunction  of  a  number  of  defects  trivial  in  themselves  so  frequently  constitutes 

20 


306  CITY  MILK  SUPPLY 

an  aggregate  that  is  serious,  that  it  is  impossible  to  even  imagine  the  proper  con- 
duct of  such  plants  without  supervision  of  an  inspectorial  nature." 

Sterilization  of  Milk  by  Electricity. — The  question  is  often  asked 
whether  it  is  possible  to  sterilize  milk  by  electricity.  The  process  of  the 
Goucher  Electric  Purifying  Co.  does  so.  The  milk  is  filtered  through 
cheese  cloth  and  absorbent  cotton  into  a  large  tank  where  it  is  kept  in 
constant  motion  to  prevent  the  cream  rising.  From  the  tank  it  is  pumped 
through  pipes  to  an  electrical  purifying  apparatus,  being  subjected  on  the 
way  to  a  steam  temperature  which  can  be  regulated  to  any  desired  degree. 
In  the  electrical  purifying  machine  the  milk  is  exposed  to  an  alternating 
current  of  1,920  to  1,960  voltage  and  7.5  to  8.5  amperage.  The  current 
is  obtained  through  a  1  to  10  transformer.  By  exposure  to  the  current 
the  milk  is  raised  in  temperature,  consequently  the  temperature  of  the 
milk  on  issuing  from  the  electrical  machine  is  the  temperature  it  had  on 
entering  it  plus  the  temperature  acquired  in  the  machine,  which  means 
that  the  final  temperature  is  in  measure  determined  by  the  degree  of 
steam  heating  it  receives.  As  the  process  is  often  operated,  the  milk  is 
heated  to  about  150°F.  by  steam  and  is  raised  to  164°F.  by  the  electrical 
apparatus.  From  the  electrical  machine  the  milk  runs  over  coolers  to  a 
bottling  tank.  The  passage  of  the  milk  from  the  receiving  tank  through 
the  steam-heated  pipes  and  electrical  machine  to  the  bottling  tank  is  said 
to  take  less  than  a  minute  so  that  the  process  partakes  of  the  nature  of 
flash  sterilization.  The  proprietors  put  out  literature  giving  the  findings 
of  several  commercial  laboratories  that  the  process  effects  a  good  bacter- 
ial reduction,  destroys  disease  germs,  does  not  alter  the  chemical  consti- 
tution of  the  milk  and  tends  to  increase  rather  than  to  decrease  the  volume 
of  the  cream  layer.  No  data  is  available  as  to  the  cost  of  purifying  milk 
by  this  process. 

Lewis  in  England  reports  tests  with  an  apparatus  for  pasteurizing 
milk  by  electricity. 

"The  current  which  varies  in  amount  with  the  size  of  the  apparatus  but 
which  normally  is  between  2,000  and  3,000  volts  is  applied  to  the  milk  by  three 
copper  electrodes,  each  of  which  is  enclosed  in  an  electrode  chamber.  The  cham- 
bers communicate  with  each  other  by  means  of  stout  glass  tubing  of  even  bore. 
The  electrode  chambers  and  the  intermediate  portions  of  glass  tubing  are  con- 
nected by  socket  joints  of  India  rubber;  the  whole  being  built  in  sections  and  fast- 
ened in  this  way  to  facilitate  cleaning  and  to  make  the  apparatus  somewhat 
flexible,  the  bore  of  the  glass  or  " lethal  tube"  is  relative  to  the  milk  output  per 
hour  of  the  particular  installation,  and  the  size  of  the  electrode  chamber  and  its 
enclosed  electrode  is  such  as  to  interfere  as  little  as  possible  with  the  flow  of  milk 
through  the  apparatus,  and  in  addition  to  allow  the  copper  electrode  to  command 
the  whole  bore  fully,  so  that  no  milk  can  escape  through  the  apparatus  without 
being  submitted  to  the  full  action  of  the  current.  The  electrode  is  of  copper 
%  in.  thick  and  is  connected  with  an  electric  cable  by  a  flat  plate  which  by  a 
spring  contact  is  forced  against  a  similar  flat  plate  directly  connected  to  the  elec- 


THE  MILK  CONTRACTOR  307 

trie  cable.  A  high-tension  current  is  used  which  in  commercial  practice  necessi- 
tates the  use  of  devices  to  protect  the  operator.  Prior  to  the  entry  into  the  lethal 
tube  the  milk  flows  through  an  aluminum  tube;  similarly,  as  the  milk  leaves  the 
apparatus  it  flows  through  a  second  aluminum  tube,  both  tubes  having  a  direct 
earth  connection.  This  arrangement  prevents  any  leakage  of  current  into  the 
containing  or  receiving  tanks.  Thus  attendants  are  protected  against  shock. 
The  lethal  tube,  with  its  high-voltage  connections,  is  mounted  on  a  slate  panel, 
itself  suspended  from  the  back  of  a  glass-panelled  upper  cupboard.  A  lower 
cupboard,  the  doors  of  which  are  automatically  closed  by  the  overlapping  doors 
of  the  upper  cupboard,  contains  the  high-voltage  transformer.  For  further  pro- 
tection, in  the  framework  of  the  two  doors  of  the  upper  cupboard,  switches  are 
placed,  which,  when  the  doors  are  open,  are  "off"  t>ut  when  the  doors  are  closed 
are  "on."  These  switches  are  connected  directly  with  the  source  of  the  electric 
current.  When,  therefore,  the  doors  are  open  the  electric  current  is  of  necessity 
"off"  and  the  apparatus  can  be  worked  only  when  the  doors  are  closed;  the  act 
of  opening  any  of  the  doors  automatically  disconnects  the  electric  current.  Thus 
the  apparatus  is  perfectly  safe  even  when  worked  by  an  operator  not  especially 
skilled  in  the  theory  and  practice  of  electricity.  The  electricity  used,  normally 
consists  of  a  low-voltage  alternating  current  which  is  passed  into  a  transformer 
and  the  voltage  increased  to  the  desired  point.  Switches  and  other  controlling 
gear  are  mounted  on  a  switchboard  from  which  the  whole  apparatus  is  worked. 
"The  course  of  the  milk  through  the  apparatus  is  from  a  receiving  tank  into 
a  constant-level  tank,  into  the  lethal  tube,  into  a  covered  channel  which  dis- 
charges into  each  of  two  auxiliary  tanks  which  empty  into  the  main  tank  for 
the  heated  milk.  In  starting  the  apparatus  the  milk  on  emerging  from  the 
lethal  tube  is  caught  in  a  separate  tank;  the  current  is  switched  on  and  regulated, 
when  the  correct  speed  of  flow  is  established,  the  temperature  of  the  milk  rises 
to  the  normal  maximum  and  the  sterilizing  process  begins.  The  milk  that  has 
heretofore  passed  the  lethal  tube  is  returned  to  the  receiving  tank  for  steriliza- 
tion. The  object  of  the  two  auxiliary  tanks  is  to  make  it  possible  to  reject  por- 
tions of  the  batch  that  for  one  reason  or  another  are  thought  to  be  imperfecly 
sterilized  before  they  reach  the  main  tank." 

The  apparatus  effects  satisfactory  reduction  in  the  number  of  bacteria 
in  the  milk,  and  wholly  destroys  any  B.  coli  and  B.  tuberculosis  that  are 
present.  It  does  not  alter  the  chemical  composition  of  the  milk. 

The  large-scale  experimental  plant  was  operated  3  months  and  in  that 
time  heated  some  9,000  gal.  of  milk  which  were  distributed  in  270,000 
bottles  for  infant  use.  The  total  cost  including  interest  and  depreciation, 
wages  and  fuel,  when  electricity  is  1.5d.  perunit  is  1.25d.  per  gallon.  In  the 
case  of  town's  gas  at  2s.  8d.  per  1,000  cu.  ft.,  the  total  cost  is  reduced  to  96 
d.  per  gallon  and  is  again  reduced  to  85d.  per  gallon  when  producer  gas, 
obtained  from  anthracite  at  30s.  per  ton,  is  used.  The  amount  of  elec- 
tricity used  is  about  0.43  units  per  gallon  of  milk. 

Sterilization  of  Milk  by  Ultraviolet  Rays. — Preliminary  experiments 
on  the  sterilization  of  milk  by  ultraviolet  rays  were  conducted  by  Ayres 
and  Johnson.  They  found  that: 


308  CITY  MILK  SUPPLY 

"1.  When  milk  is  exposed  in  thin  layers  to  ultraviolet  rays  there  was  a  marked 
reduction  in  bacterial  content.  (2)  That  since  the  temperature  of  the  exposed 
milk  never  rose  above  86°F.,  the  action  of  the  rays  was  entirely  independent  of 
the  action  of  heat.  (3)  The  most  satisfactory  method  of  exposure  was  over  two 
revolving  drums,  the  tops  of  which  were  at  a  distance  of  4  in.  below  the  light  tube 
of  the  lamp.  (4)  The  two  factors  of  greatest  importance  in  the  successful  appli- 
cation of  the  rays  were  the  thickness  of  the  layer  and  the  length  of  exposure. 
A  thin  layer  permits  a  more  complete  penetration  of  the  rays  and  the  longer  the 
exposure  the  more  chance  they  have  to  act.  (4)  Ultraviolet  rays  exerted  a 
greater  bactericidal  action  on  vegetative  cells  in  milk  than  on  spores  when  ex- 
posed under  the  same  conditions.  (6)  No  greater  action  of  the  rays  on  bacteria 
was  observed  when  the  bacteria  were  weakened  by  pasteurization  immediately 
preceding  exposure.  (7)  From  the  study  of  two  samples  of  milk  exposed  to 
ultraviolet  rays  it  was  apparent  that  the  rays  did  not  exert  any  specific  bacteri- 
cidal power  on  any  particular  group  of  bacteria  in  the  milk.  As  stated  before, 
however,  there  was  a  difference  on  the  action  of  the  rays  on  bacteria  in  the  vege- 
tative and  spore  state.  (8)  Under  similar  conditions  of  exposure  there  seemed 
to  be  somewhat  less  bacterial  reduction  in  15  per  cent,  cream  than  in  milk  which 
was  probably  because  the  revolving  drums  picked  up  a  thicker  cream  layer  than 
milk  layer.  (9)  When  milk  was  exposed  under  conditions  suitable  for  a  satis- 
factory reduction  of  the  bacteria  by  the  ultraviolet  rays  there  was  also  produced 
an  abnormal  disagreeable  flavor  that  would  render  the  milk  unsaleable.  (10) 
A  large  percentage  of  the  bacteria  in  normally  dirty  and  artificially  infected  milk 
bottles  were  destroyed  by  exposure  to  the  rays." 

The  best  results  were  obtained  when  the  bottles  were  exposed  directly 
under  the  lamp,  the  top  of  the  bottle  being  about  4  in.  from  the  lamp  tube. 
When  bottles  were  exposed  on  one  side  of  the  lamp  and  not  directly  under 
it,  poor  results  were  obtained.  It  was  not  possible  to  completely  ster- 
ilize the  bottles  even  after  a  10-min.  exposure.  The  authors  concluded 
that  with  quartz  mercury  vapor  lamps  of  the  present  power  and  con- 
struction it  would  not  be  possible  to  completely  sterilize  milk  by  the  ul- 
traviolet rays;  that  while  by  the  use  of  large  drums  and  many  lamps 
bacterial  reductions  as  great  as  are  now  secured  by  pasteurization  might 
be  obtained,  there  is  no  assurance  that  the  disease  germs  would  be  killed, 
since  the  rays  do  not  exert  a  selective  action  on  vegetative  cells ;  that  on  a 
commercial  scale  it  would  be  difficult  to  control  the  factors  which  influence 
the  bactericidal  action  of  the  rays  and  moreover  the  disagreeable  flavor 
imparted  to  the  milk  renders  the  process  impracticable ;  that  it  is  doubtful 
whether  the  lamps  could  be  made  to  compete  with  the  use  of  steam  in 
sterilizing  the  bottles. 

Houghton  and  Davis  confirm  the  conclusion  of  Ayres  and  Johnson 
that  the  untraviolet  rays  cannot  be  successfully  used  to  sterilize  milk 
and  state  that  in  this  respect  their  work  agrees  with  that  of  Romer  and 
Sames  and  of  Juyge.  They  did  not  find  a  perceptible  change  in  the  flavor 
of  the  milk  after  it  was  illuminated. 


THE  MILK  CONTRACTOR 


309 


TABLE   86. — RESULTS   OP   TESTS   AT   FIVE    MILK-PASTEURIZING   PLANTS    (BOWEN) 

Temperature  balance 


l(a) 

2  (a) 

3(6) 

4(c) 

5(d) 

Raw  milk,  °F  :  

63.50 

57.86 

59.40 

54.00 

47.60 

Regenerator,  °F.                 

131  30 

107  .  50 

124  00 

Rise  in  regenerator,  °F. 

71  90 

53  50 

76  50 

Rise,  per  cent  

84  00 

60  53 

78.30 

Heater,  °F. 

146  00 

150  40 

145  00 

142  40 

145  30 

Rise  in  heater,  °F  

82.50 

92.54 

13  70 

34  90 

21.20 

Rise,  per  cent.   .                           ... 

16  00 

39  47 

21  70 

Total  rise,  per  cent  

. 
100.00 

100.00 

100  00 

100.00 

100.00 

Holder,  °F  

146.00 

150.40 

145  00 

142  .  40 

143.30 

Drop  in  holder,  °F  ,  
Drop,  per  cent 

8.00 
9  70 

4.24 
4  58 

2.25 
2  63 

1.33 
1  50 

3.90 
3  99 

Regenerator,  °F  
Drop  in  regenerator,  °F. 

138.00 
29  75 

146.16 
34  16 

142.75 
63  45 

141.07 
57  07 

141.40 
83  00 

Drop,  per  cent  
Cooler  °F 

36.00 
108  25 

36.85 
112  00 

74.12 

7Q    QQ 

64.50 
84  00 

84.96 
56  00 

Drop  in  cooler,  °F  
Drop,  per  cent.  .  . 

44.75 
54  30 

54.14 
58  57 

19.90 
23  25 

30.00 
34  00 

10.80 
11  05 

Total  drop,  per  cent  

100.00 

100  00 

100  00 

100  00 

100  00 

COSTS 


Capital  invested  in  pasteurizing  equip- 
ment —  pasteurizers,  vats,  coolers,  etc.  .  . 
Interest  per  day  on  investment  at  6  per 
cent,  per  annum 

$5,332 
0.876 
3.652 

1,000 
0.164 

0.274 
3.500 
1.032 

0.848 
0.480 

$3,000 
0.493 
2.055 

800 
0.131 

0.219 
1.750 
0.582 

0.480 
0.460 

$2,065 
0.339 
1.414 

380 
0.049 

0.082 
1.500 
0.166 

0.109 
0.206 

$3,470 
0.570 
2.380 

500 
0.087 

0.137 
3.000 
0.634 

0.158 
1.700 

$6,250 
1.027 
4.281 

700 
0.115 

0.192 
3.000 
0.425 

0.009 
0.886 

Depreciation  and  repairs  per  day  at  25 
per  cent,  per  annum  .  . 

Capital   invested   in   mechanical   equip- 
ment   used    for    pasteurizing  —  engine, 
boiler-shafting,  etc. 

Interest  per  day  on  investment  at  6  per 
cent,  per  annum  

Depreciation  and  repairs  per  day  at  10  per 
cent,  per  annum  

Labor  for  pasteurizing 

Cost  of  coal  at  $4  per  ton  of  2,240  ton  
Cost  of  cooling  water  at  50  cts.  per  1,000 
cu.  f  t  

Cost  of  refrigeration  at  $1  per  ton  

Cost  of  pasteurizing  daily  supply  of  milk  .  . 
Cost  of  pasteurizing  1  gal.  of  milk  

10.826 
0.00229 

0.00313 

6.170 
0.00262 

3.865 
0.00436 

8.666 
0.00251 

9.935 
0.00387 

Average  cost  for  the  five  plants  of  pas- 
teurizing 1  gal.  of  milk 

(a)  Regenerator  in  heater.     (6)    Surface  cooler  used  as  regenerator,     (c)   Direct 
expansion  coils  in  cooler,     (d)  Cooled  entirely  by  refrigerated  water. 


310  CITY  MILK  SUPPLY 

Cost  of  Pasteurization. — The  average  cost  of  pasteurization  is  difficult 
to  determine  because  it  varies  a  good  deal  in  different  localities,  being- 
dependent  on  the  price  of  labor,  of  coal,  on  the  capital  invested  in  machin- 
ery, on  the  temperature  of  the  milk  when  received  at  the  plant  and  on 
other  factors  of  moment.  Bowen  for  the  U.  S.  Department  of  Agriculture 
investigated  the  cost  of  pasteurizing  milk  at  five  representative  milk 
plants  and  of  cream  at  four  cream-pasteurizing  plants.  All  of  the  city 
milk  plants  used  the  holder  process  whereas  but  two  of  the  cream- 
pasteurizing  plants  did  so. 

Some  of  Bowen's  results  at  the  city  milk  plants  are  given  in  Table  86. 

Bowen  also  made  tests  of  the  cream-pasteurizing  apparatus  at  four  creameries. 
The  apparatus  represented  both  the  flash  and  holder  type  of  machines  and  pasteuriza- 
tion was  accomplished  by  using  (1)  live  steam,  (2)  exhaust  steam  from  the  engine  or 
from  steam-driven  pumps  and  (3)  hot  water  heated  by  exhaust  steam  from  steam- 
driven  auxiliaries.  The  acutal  cost  of  pasteurizing  cream  at  each  of  the  four  plants 
was  $0.0456,  $0.0701,  $0.765,  and  $0.1101. 

The  conclusions  reached  by  Bowen  were  that : 

"1.  The  flash  process  requires  about  17  per  cent,  more  heat  than  the  holder, 
process,  consequently  the  milk  or  cream  must  be  cooled  through  a  wider  range, 
hence  both  add  to  the  cost  of  pasteurizing. 

"2.  The  proper  design  and  arrangement  of  the  heater,  regenerator,  cooler, 
piping  and  refrigerating  apparatus  have  much  to  do  with  the  efficient  operation 
of  the  plant. 

"3.  The  loss  in  heat  from  poorly  arranged  apparatus  and  leaky  piping  may 
amount  to  approximately  30  per  cent,  of  the  total  amount  of  heat  required  to 
pasteurize  and  it  is  practicable  to  reduce  this  loss  to  a  negligible  amount. 

"4.  It  is  practicable  to  use  exhaust  steam  from  the  engine  and  steam-driven 
auxiliaries,  or  water,  heated  by  exhaust  steam,  to  furnish  heat  wherewith  to  pas- 
teurize both  milk  and  cream.  Milk  plants  usually  waste  enough  heat  in  the 
exhaust  to  do  the  pasteurizing. 

"5.  For  every  400  Ib.  of  milk  pasteurized  per  hour  with  exhaust  steam  ap- 
proximately 1  hp.  is  taken  off  the  boiler  plant. 

"6.  The  average  cost  of  pasteurizing  1  gal.  of  milk  is  $0.00313  and  1  gal.  of 
cream  $0.00634." 

These  figures  of  Bowen's  deal  with  the  pasteurizing  cycle  proper,  that 
is,  starting  with  the  initial  temperature  of  the  raw  milk  and  raising  its 
temperature  to  the  pasteurizing  point  and  then  cooling  the  milk  to  the 
initial  temperature  of  the  raw  milk.  They  show  the  additional  expense 
of  producing  pasteurized  milk  over  the  raw  product.  The  results  of 
Bowen's  tests  have  been  quoted  only  in  part  and  the  reader  is  advised 
to  consult  the  original  paper. 

With  regard  to  the  present  use  of  pasteurization  it  may  be  said  that 
butter  and  cheese  makers  have  wisely  adopted  the  flash  process.  In  the 


THE  MILK  CONTRACTOR  311 

city  milk  business,  taking  the  country  by  and  large,  probably  more  plants 
are  using  the  flash  process  but  the  health  codes  of  the  largest  cities  and 
of  the  most  progressive  large  and  small  ones  require  the  use  of  the  holder 
process.  It  is  slowly  and  steadily  superseding  the  flash  method  and  will 
probably  ultimately  come  to  be  the  only  process  applied  to  pasteurizing 
milk  for  direct  consumption. 

There  are  two  reasons  for  the  existence  of  so  many  plants  of  the  flash 
type,  namely:  (1)  that  in  regions  where  pasteurization  is  being  newly 
introduced  and  without  restrictions  imposed  by  boards  of  health  it  is  apt 
to  be  selected  because  the  first  cost  of  installation  is  often  considerably 
less  than  for  the  holder  process;  and  (2)  in  many  places  the  flash  process 
is  used  merely  because  it  was  installed  before  the  holder  process  was 
developed  and  its  merits  appreciated. 

Future  of  Pasteurization. — With  regard  to  the  future  of  pasteurization 
it  may  be  confidently  predicted  that  all  of  the  cities  of  the  United  States 
that  are  able  to  afford  pasteurizing  plants  will  adopt  them  as  necessary 
instruments  to  cope  with  the  milk  problem.  Three  reasons  assure  this, 
namely:  (1)  in  the  present  state  of  preventive  medicine  it  is  the  only  way 
to  protect  the  milk-  consuming  public  from  the  dangers  of  chance  infection 
to  which  even  the  best  of  milk  is  liable;  (2)  the  expense  of  maintaining  a 
close  inspection  of  distant  and  widely  scattered  dairy  farms  is  prohibitive 
and  in  fact  none  of  the  large  cities  or  various  State  boards  charged  with 
such  work  pretend  to  carry  on  such  inspection ;  and  (3)  it  is  an  economic 
necessity  to  pasteurize  milk  in  order  to  prevent  great  loss  ensuing  from 
the  growth  of  large  numbers  of  microorganisms  therein.  While  this  wide 
use  of  pasteurization  is  bound  to  come,  it  is  nevertheless  true  that  there 
is  some  danger  that  the  friends  of  the  process  may  injure  its  good  reputa- 
tion. Pasteurized  milk  should  be  sold  for  exactly  what  it  is  and  pasteur- 
ization should  neither  be  touted  as  a  cure-all  nor  represented  as  making 
milk  absolutely  safe.  Pasteurized  milk  should  be  plainly  labeled  such 
and  the  label  should  state  the  date,  time  and  temperature  of  pasteuriza- 
tion. In  some  quarters  there  seems  to  be  a  tendency  to  try  to  persuade 
that  pasteurization  may  be  safely  accepted  in  lieu  of  dairy  inspection 
and  as  guaranteeing  absolute  protection  from  tuberculosis.  Dairy  in- 
spection has  its  place  for  the  health  officer  certainly  ought  to  know  where 
the  milk  that  is  served  within  his  jurisdiction  comes  from  and  to  be 
familiar  with  the  farm  and  farmers  who  are  producing  it  and  also  with 
the  methods  used  in  handling  it.  Without  this  knowledge  it  is  doubtful 
if  the  health  code  can  be  either  intelligently  framed  or  administered  and 
dairy  practice  is  more  likely  to  become  woefully  slack  rather  than  to 
keep  abreast  of  the  times.  In  combating  tuberculosis  pasteurization  is 
a  valuable  weapon;  it  all  but  prevents  children  from  contracting  the  dis- 
ease from  milk  and  if  used  intelligently  in  connection  with  tuberculin 
testing  helps  to  eradicate  the  disease  at  a  minimum  cost,  but  to  preach 


312 


CITY  MILK  SUPPLY 


the  doctrine  that  it  offers  absolute  protection  against  this  or  any  other 
disease  is  to  deceive.  Pasteurization  is  a  mechanical  process  operated 
by  men  and  in  this  imperfect  world  both  fail  at  times,  so  that  a  very  high 
degree  of  protection  is  the  most  that  can  be  honestly  promised.  The 
process  may  be  likened  to  the  mechanical  nitration  of  water;  this  sort  of 
water  treatment  when  operated  efficiently  with  machinery  in  first-class 
condition  is  capable  of  materially  reducing  water-borne  diseases,  but  if 
the  apparatus  breaks  down  or  is  allowed  to  get  into  Condition  unfit  for 
use  or  if  it  is  either  incompetently  or  dishonestly  operated  it  will  fail 
in  greater  or  less  degree  according  to  the  gravity  of  the  injury  or 
mismanagement. 

Pasteurization  of  milk  is  accepted  as  a  necessary  treatment  of  the 
public  milk  supply  not  because  it  is  ideal  but  because  it  is  practicable. 
When  the  pasteurization  is  done  right  and  the  milk  protected  against 
subsequent  infection  and  when  the  pasteurized  milk  is  marketed  on  its 
merit  without  extravagant  claims  in  its  behalf  the  process  is  a  great  boon 
to  the  milk  consumer,  but  when  the  milk  is  pasteurized  in  any  old  way 
that  will  prevent  souring,  or  when  milk  is  pasteurized  over  and  over  again 
before  the  consumer  gets  it,  or  when  pasteurization  is  used  as  a  club  to 
kill  off  inspection  of  dairy  farms  or  tuberculin  testing  or  any  other  legiti- 
mate phase  of  control  of  the  milk  supply,  it  can  be  made  a  curse  instead  of 
a  blessing.  The  process  probably  has  enough  intrinsic  merit  to  survive 
any  abuse  to  which  it  is  likely  to  be  subjected  but  if  dairymen  and  their 
customers  are  to  enjoy  in  full  the  benefits  it  is  capable  of  conferring  it 
must  be  used  honestly  under  severe  inspection. 

Use  of  Pasteurization  in  the  United  States. — The  general  tendency 
in  the  United  States  at  the  present  time  is  toward  the  pasteurization  of 
all  market  milk  except  that  which  is  certified  and  that  which  comes 
from  tuberculin-tested  herds.  This  trend  may  be  observed  in  Tables  87 
and  88. 


TABLE  87. — THE  EXTENT  OP  USE  OF  PASTEURIZATION  IN  CITIES  OF  THE  UNITED  STATES 
OF  A  POPULATION  ABOVE  25,000  (AYRES) 


Population 

No.  cities 
replying 

More  than  50 
per  cent, 
pasteurized 

11  to  50  per 
cent, 
pasteurized 

0  to  10  per 
cent, 
pasteurized 

None  pas- 
teurized 

More  than  500,000.... 

9 

7 

2 

0 

0 

100,001  to  500,000  .  .  . 

40 

12 

20 

6 

2 

75,001  to  100,000.  .  .  . 

19 

5 

8 

4 

2 

50,001  to    75,000.  .  .  . 

30 

4 

15 

6 

5 

25,001  to    50,000.  .  .  . 

78 

13 

31 

12 

22 

10,001  to    25,000.  .  .  . 

168 

10 

40 

18 

100 

Total         

344 

51 

116 

46 

131 

THE  MILK  CONTRACTOR 


313 


TABLE  88. — PERCENTAGE  OF  THE  MILK  SUPPLY  OP  Six  CITIES  OP  THE  UNITED  STATES 
THAT  is  PASTEURIZED  (AYRES) 

Boston,  Mass 80       Philadelphia,  Pa 85 

Chicago,  111 80       Pittsburgh,  Pa 95 

Detroit,  Mich 571     St.  Louis,  Mo. 70 

New  York,  N.  Y 88 

1  In  1916  practically  all  milk  intended  for  direct  consumption  must  be  pasteurized. 


Courtesy  of  George  M.  Oyster,  Jr. 

FIG.  43. — Milk  handling  room  of  the  Chestnut  Farms  Dairy,  Washington,  D.  C- 
1st  floor:  Roller  conveyer,  rotary  fillers,  capping  machines,  and  cooler. 
2d  floor:  Pasteurizing  vats  with  automatic  temperature  recorders. 
3d  floor:  Cooler  and  storage  tanks  for  cream  and  buttermilk. 
4th  floor:  Receiving  vats. 

Cooling  Milk. — After  pasteurization,  milk  is  cooled,  bottled  and 
capped,  usually  in  a  single  room  known  as  the  milk-handling  room,  that 
is  kept  immaculately  clean,  is  free  from  dust  and  odors,  is  often  wet  down 
with  steam  before  work  begins  and  that  while  work  is  in  progress  is  closed 
to  every  one  save  the  few  white-suited  men  who  are  cooling  and  putting 
up  the  milk.  Cooling  begins  right  after  the  milk  is  pasteurized.  There 
are  several  types  of  coolers  in  use.  In  the  country  most  of  the  milk  is 
cooled  by  putting  the  cans  containing  it  into  tanks  of  cold  water.  Very 
commonly,  too,  dairy  farmers  who  retail  their  milk  cool  it  with  a  Cham- 
pion cooler,  a  galvanized-steel  bottomed,  open-top  cone  of  heavy  tin- 


314  CITY  MILK  SUPPLY 

plate.  Water  and  ice  are  put  inside  the  cone  and  stirred  frequently 
with  an  agitator  to  keep  the  cold  water  against  the  cone  or  cold  water 
is  circulated  through  the  cone  through  an  inlet  pipe  at  the  bottom  and 
an  outlet  pipe  at  the  top.  From  a  reservoir  on  top  of  the  cone  milk  is 
discharged  through  perforated  holes  onto  the  cold  outer  surface  of  the 
cone  and  is  cooled  as  it  runs  down  in  a  thin  sheet  into  a  trough  at  the 
bottom  whence  it  drains  into  a  receiving  can.  Except  in  the  hotter 
dairy  sections  and  those  where  neither  cold  water  nor  ice  are  generally 
available  this  simple  machine  has  proved  a  very  useful  one. 

The  Star  type  of  cooler  also  is  much  used  by  small  dairymen,  particu- 
larly for  cooling  cream.  It  is  made  of  two  sheets  of  heavily  tinned  copper 
bent  into  corrugations  and  so  soldered  together  at  the  ends  that  a  space 
is  left  between  the  sheets  for  water  to  circulate.  Thus  the  cooler  has 
a  fluted  surface  over  which  the  milk  flows  in  a  thin  film.  Water  is  intro- 
duced to  the  cooler  at  the  bottom  and  passes  out  at  the  top  while  the  milk 
runs  from  a  tank  into  a  perforated  distributing  trough  at  the  top  of  cooler 
and  down  over  the  cold  surface  of  the  cooler  into  a  trough  and  out  through 
a  spout  into  a  receiving  can.  This  is  a  good  cooler  but  a  frail  one,  for  it 
is  made  of  such  thin  metal  to  insure  a  rapid  exchange  of  heat  between  the 
warm  milk  and  the  cold  water  that  it  is  easily  injured  by  rough  handling 
in  washing  it,  or  by  dropping  it  on  the  floor  or  by  forcing  water  through 
it  under  too  great  head. 

In  another  type  of  cooler  the  milk  flows  from  a  tank  into  a  perforated 
distributing  trough  and  over  heavily  tinned  corrugated  copper  cylinders 
that  are  set  horizontally  in  cast-iron  supporting  racks  and  vertical  water 
columns  from  which  they  may  be  removed  for  cleaning.  The  cylinders 
are  cooled  by  circulating  water  or  brine  through  them  or  by  circulating 
brine  through  the  lower  cylinders  and  water  through  the  upper >v ones. 
The  water  or  brine  is  introduced  at  the  bottom  of  the  water  column  at 
one  side  of  the  cooler,  runs  through  the  bottom  cylinder  up  through  the 
water  column  at  the  other  side,  up  it  and  back  through  the  next  cylinder 
to  the  first  water  column,  up  it  into  the  third  cylinder,  and  so  on  till  it 
passes  out  of  the  cooler  at  the  top  of  the  first  water  column.  The  cylin- 
ders are  corrugated  to  slacken  the  flow  of  milk  over  them  and  are  repre- 
sented to  be  very  strong.  The  great  advantage  of  this  type  of  coolers 
is  that  they  are  easily  taken  apart  for  cleaning. 

Coolers  of  the  continuous-surface  type  are  so  built  that  an  unbroken 
surface  on  both  sides  is  presented  for  the  milk.  Horizontal,  round  or 
triangular  tubes  are  united  by  tinned  brass  strips  carefully  soldered  to 
the  tubes,  making  the  cooler  section  a  rigid  unit.  The  advantages 
claimed  for  the  triangular  tubes  are  that  they  offer  a  maximum  of  cooling 
surface  in  a  little  space  and  that  they  retard  the  downward  flow  of  milk 
over  the  cooling  board.  Water  or  brine  is  circulated  from  bottom  to 
top  of  the  board  through  the  system  of  tubes  and  the  milk  is  cooled  as  it 


THE  MILK  CONTRACTOR  315 

passes  over  them,  down  the  surface  of  the  board.  Sometimes  the  upper 
tubes  are  constructed  for  cooling  with  water  while  the  lower  ones  are 
made  of  special  ammonia  piping  for  direct-expansion  ammonia  from  a 
refrigerating  machine.  By  employing  direct  expansion  instead  of  brine 
for  the  final  cooling  the  use  of  a  brine  pump,  brine  tank  and  coils  or  brine 
cooler  is  obviated  and  the  attendant  losses  avoided.  Screw  plugs  are 
provided  at  both  ends  of  each  tube  so  that  the  tubes  can  be  thoroughly 
cleaned,  a  necessary  provision  because  many  waters  deposit  an  incrusta- 
tion of  mineral  salts  within  the  tubes,  thus  impairing  their  conductivity 
and  so  their  cooling  efficiency. 

In  the  spiral-conical  coolers  the  water  enters  at  the  bottom  and  travels 
in  a  spiral  course  through  a  small  tube  around  a  tinned  copper  shell  or 
cone  and  discharges  at  the  top  into  a  cavity  beneath  the  bowl  or  milk- 
distributing  reservoir,  whence  it  overflows  into  the  outlet  pipe.  The 
milk  is  fed  from  the  bowl  into  the  outer  surface  of  the  cone  and  flows 
spirally  downward  over  the  cold  surface  of  the  water  tube  to  a  trough  at 
the  bottom  of  the  cone  whence, it  is  discharged  into  a  receiving  can  at 
approximately  the  temperature  of  the  cooling  water.  Thus  efficiency  is 
gained  by  the  retarding  effect  of  the  spiral  path  of  the  milk,  by  bringing 
the  milk  in  its  progress  downward  in  contact  with  a  surface  that  grows 
constantly  cooler  and  by  the  construction  of  the  spiral  itself  which  is  such 
as  to  spread  the  milk  in  a  thin  film  over  the  maximum  of  surface  in  the 
corrugations  toward  the  bottom. 

The  advantages  claimed  for  this  type  of  cooler  are  compactness  of 
design,  occupancy  of  a  minimum  of  floor  space  per  unit  of  capacity,  high 
cooling  efficiency,  accessibility  for  cleaning  and  a  convenient  mantle 
enclosure. 

The  demand  for  absolutely  enclosed  coolers  has  led  to  the  use  of  tubu- 
lar coolers.  They  are  identically  the  sam'e  machines  as  the  tubular  heat- 
ers that  are  used  for  pasteurizing  milk  but  instead  of  heating  the  milk 
in  the  inner  tube  or  tubes  with  hot  water  it  is  chilled  with  cold  water  or 
brine.  The  milk  in  the  inner  tubes  circulates  in  a  direction  contrary  to 
that  of  the  water  so  that  the  milk  in  its  progress  is  brought  into  contact 
with  colder  and  colder  water.  These  coolers  are  economical  and  efficient 
and  besides  protect  the  milk  from  contamination  from  the  air,  prevent  the 
considerable  loss  that  occurs  with  open  coolers  from  evaporation,  may  be 
sterilized  under  pressure  and  since  they  are  erected  in  sectional  units 
may  be  expanded  as  the  business  grows.  The  drawbacks  are  that  the 
milk  may  be  contaminated  by  leakage  and  that  it  is  difficult  to  draw  off 
all  of  the  milk  at  the  end  of  the  run.  These  coolers  are  in  use  in  some  of 
the  largest  and  best  plants. 

Many  of  the  above  types  of  coolers  can  be  used  as  regenerative  coolers, 
by  running  the  cold  milk  en  route  to  the  heaters  through  the  upper  sections 
of  the  cooler,  thereby  reducing  the  temperature  of  the  hot  milk  from  the 


316  CITY  MILK  SUPPLY 

heaters,  holders  and  retarders  which  yields  its  heat  to  the  cold  milk  as  it 
flows  over  these  sections  and  which  is  finally  thoroughly  cooled  in  passing 
over  the  lower  sections  through  which  cold  water  or  brine  runs.  These 
regenerative  coolers  are  economical  and  are  commendable  if  they  receive 
proper  care  but  they  are  to  be  condemned  if  they  are  not  cleaned  thor- 
oughly and  regularly  for  so,  the  milk  in  passing  them  is  contaminated. 

In  choosing  a  cooler,  the  quantity  of  milk  to  be  handled,  the  tempera- 
ture to  which  the  milk  is  to  be  reduced  and  the  suitability  of  the  machine 
for  the  plant  should  be  considered.  The  capacity  of  the  cooler  is  largely 
determined  by  the  area  of  cooling  surface  and  by  construction  such  that 
a  good  circulation  of  the  cooling  medium  can  be  maintained.  The  econo- 
my of  the  circulation  must  also  be  considered  for  where  water  is  scarce 
or  water  rates  high  it  may  be  an  important  item. 

With  open  coolers  the  temperature  of  the  room  wherein  the  cooling 
is  done  has  some  effect.  Thus  in  summer  when  the  cooling  is  being  done 
with  cold  water  it  may  be  necessary  to  run  the  milk  over  the  cooler  twice 
to  reduce  it  to  approximately  the  temperature  of  the  water,  when  in  win- 
ter once  would  suffice.  It  is  impracticable  to  reduce  the  temperature  of 
milk  much  below  50°F.  in  summer  without  the  use  of  ice  or  a  refrigerating 
machine.  With  ice  water  as  the  cooling  medium,  only  with  difficulty 
can  the  milk  be  cooled  much  below  40°F.  while  with  brine,  the  tem- 
perature may  easily  be  brought  down  to  34°F.  In  cooling  milk,  the 
temperature  should  be  taken  occasionally  with  a  good  thermometer 
to  assure  the  operator  that  he  is  really  getting  good  results. 

Many  cities  now  require  that  open  coolers  be  enclosed  with  a  cover 
to  protect  the  milk  as  it  flows  over  the  cooler  from  contamination  from  the 
air.  This  is  regarded  as  of  particular  consequence  in  cities,  where  air 
is  likely  to  be  sooty  and  dusty  and  more  or  less  fecally  polluted.  Of  more 
importance  is  it  to  see  that  the  cooler  is  perfectly  clean  and  sterile  before 
any  milk  is  run  over  it.  Of  course  the  cooler  must  be  thoroughly  cleaned 
after  each  run  but  even  when  this  has  been  properly  attended  to  dust  is 
likely  to  have  settled  on  the  apparatus  in  the  interim  between  the  clean-up 
and  the  time  for  the  next  run.  Hence  the  need  of  thorough  rinsing 
and  steaming  before  starting.  Bacterial  tests  have  shown  that  the  first 
milk  over  the  cooler  is  apt  to  show  a  higher  count  than  that  which  comes 
over  later,  the  explanation  of  which  is,  that  the  first  milk  washes  off  the 
cooler.  In  pasteurizing  plants  the  first  milk  from  the  machines  is  likely 
to  have  a  high  bacterial  count  because  they  have  not  settled  down  to 
uniform  operation;  therefore,  this  first  milk  should  not  be  run  over 
the  cooler  to  contaminate  it,  but  should  be  returned  for  repasteurization. 

Filling  the  Bottles. — As  soon  as  milk  is  cooled  it  is  put  into  cans  and 
removed  to  a  cold  room  or  it  is  bottled.  Small  dairymen  fill  their  bottles 
by  hand  with  a  filling  dipper  but  this  is  a  tedious  job  and  those  who 
can  afford  something  better  use  an  inexpensive  machine  that  enables 


THE  MILK  CONTRACTOR  317 

them  to  work  about  five  times  as  fast.  It  consists  of  a  tank  with  four 
castors  that  travel  on  runners  at  each  side  of  a  table  wide  enough  to  hold 
four  quart  bottles.  Four  nickel-plated  brass  valves  that  are  opened  and 
closed  by  a  lever  are  at  one  end  of  the  tank  which  is  rolled  over  the  first 
four  bottles,  the  lever  raised  and  the  bottles  filled  when  the  tank  is  pushed 
over  the  next  four  and  the  operation  repeated  and  so  on  till  all  the  bottles 
on  the  table  are  filled  when  they  are  capped,  washed  off  and  put  in  crates 
by  hand.  These  machines  with  their  solid  metal  valves  are  easily  kept 
clean  but  the  valves  in  time  wear  and  leak. 

Larger  dairymen  use  fillers,  the  tanks  whereof  are  mounted  on  a  sub- 
stantial galvanized  iron  framework  and  have  four  to  a  dozen  valves  at 
one  or  both  ends  of  the  tanks  and  are  operated  by  a  hand  lever  that  lifts 
the  crate  holding  the  bottles  and  presses  their  mouths  against  the  valves 
in  such  a  way  as  to  open  them  and  let  the  milk  run  in.  Milk  is  usually 
delivered  into  the  bottles  in  such  a  way  that  it  runs  down  their  sides  and 
so  foaming  is  greatly  reduced.  An  air  tube  in  each  valve  allows  the  foam 
and  surplus  milk  to  escape  from  the  bottle.  When  the  bottles  are  filled 
the  lever  is  lowered,  the  crate  drops  and  the  valves  close.  If  all  the  bottles 
in  a  case  are  filled  at  a  time,  they  are  capped  forthwith  but  if  only  four  are 
filled  the  crate  is  moved  forward  and  four  more  bottles  filled  while  the 
operator  caps  the  full  bottles.  Such  machines  as  this  fill  24  quart  bottles 
a  minute.  The  tanks  of  these  machines  are  usually  of  heavily  tinned 
copper  with  rounded  corners  and  with  all  seams  soldered  smoothly.  Some 
of  them  have  a  gate  so  that  the  milk  can  be  quickly  drawn  off  into  cans. 
In  some  instances  the  tanks  are  of  enamelware  but  on  the  whole  this 
material  cannot  be  commended  because  it  chips,  leaving  rough  spots  and 
cracks  that  cannot  be  properly  cleaned.  The  valves  need  careful  atten- 
tion. They  usually  consist  of  an  air  tube,  stem,  sleeve,  spring  and  rubber 
tip ;  in  some  patterns  there  are  nuts  and  -threads  besides  rubber  washers 
and  jackets;  consequently,  unless  the  valves  are  made  so  that  they  can  be 
easily  taken  apart  in  such  a  way  that  each  part  can  be  separately  cleaned, 
they  are  likely  to  become  very  foul  and  contaminate  every  bottle  of  milk 
that  is  filled.  When  the  valves  are  of  proper  design  and  are  kept  clean 
these  fillers  are  excellent  but  when  the  valves  are  patterned  so  that  the 
rubbers  and  other  parts  cannot  be  detached  or  when  the  cleaning  of  the 
machine  is  neglected,  they  are  abominable.  Case-moving  devices  are 
often  attached  to  the  stands. 

Within  the  last  four  years  rotary  fillers  and  cappers  have  been  put  on 
the  market  and  have  found  acceptance  by  the  largest  concerns.  The 
milk  is  held  in  a  round  tank  with  10  valves  in  the  bottom.  A  revolving 
conveyor  carries  the  bottles  in  single  file  beneath  the  tank  when  each 
bottle,  in  turn,  as  it  arrives  in  position  beneath  a  valve  is  automatically 
raised,  thus  opening  the  valve  and  filling  the  bottle  as  it  travels  in  a  cir- 
cular path  beneath  the  tank.  When  it  completes  the  circuit  the  bottle  is 


318  CITY  MILK  SUPPLY 

automatically  lowered,  the  valve  closed  and  the  bottle  carried  by  the 
conveyor  beneath  an  automatic  capping  machine  which  caps  it  as  it  is 
traveling  on  to  the  place  where  a  man  feeds  bottles  into  the  conveyor  and 
puts  the  capped  ones  into  crates.  The  remarks  on  valves  in  the  preced- 
ing paragraph  apply  to  those  in  use  on  the  rotary  fillers.  These  machines 
afford  excellent  opportunity  to  inspect  the  bottles  thoroughly  and  they 
work  fast,  filling  and  capping  38  to  54  quart  bottles  a  minute. 

The  very  largest  city  milk  plants  are  using  automatic  power-driven 
machines  that  fill  and  cap  six  to  eight  cases  of  quart  bottles  a  minute. 

Bottle  Caps. — Small  dealers  cap  bottles  by  hand,  somewhat  larger 
ones  use  hand-capping  machines  of  various  sorts  and  the  big  ones  sta- 
tionary machines  that  work  very  fast.  Some  of  the  machines  are  rented 
by  the  dealers,  of  the  manufacturers  who  for  various  reasons  prefer  to 
retain  the  ownership. of  them.  Formerly  milk  bottles  with  " lightning 
tops"  were  in  general  use.  These  tops  were  of  tin  plate,  were  wired  fast 
to  the  bottle  and  were  open  and  shut  by  a  bail  that  fitted  the  neck  of  the 
bottle  when  the  cap  was  closed.  The  tin  top  sat  flat  on  top  of  the  rim  of 
the  bottle  and  to  prevent  leakage  a  thin  pliable,  fiber  cap  was  put  under 
it.  These  tin  tops  rusted,  got  out  of  repair,  leaked  more  or  less  and  inter- 
fered with  the  cleaning  of  the  bottles  so  that  they  fell  into  disuse  when 
the  Thatcher  Manufacturing  Co.  brought  out  the  common-sense  bottle 
cap  in  1889. 

The  feature  of  this  bottle  is  that  within  the  neck  is  a  shoulder  or  cap- 
seat  that  holds  the  cap,  a  stiff  parffined  fiber  disc,  in  place.  This  cap 
gave  general  satisfaction  and  is  in  common  use.  In  time  the  criticism 
was  made  that  cleanliness  and  safety  demand  that  the  whole  mouth  of  the 
bottle  be  covered  to  protect  it  from  dirt,  the  drivers'  fingers  and  possible 
infection.  Such  caps  were  soon  put  on  the  market  and  are  now  supplied 
to  customers  that  can  afford  to  pay  for  them.  The  Crown  Cap  and 
Seal  Co.  in  1910  put  out  a  small-mouthed  milk  bottle  and  a  special 
"Dacro"  metal  cap  to  fit  it.  The  Standard  Cap  and  Seal  Co.  later 
brought  out  a  fiber  cap  that  completely  covers  the  top  of  the  milk  bottle 
to  which  it  is  fastened  with  a  wire  ring.  Each  of  these  companies  has  its 
capping  machines.  Many  dealers  are  putting  out  their  certified  milk 
and  cream  with  a  common-sense  cap  over  which  is  placed  a  fiber  or  foil 
cap  'that  completely  covers  the  bottle. 

Cost  of  Bottling  Milk. — The  cost  of  bottling  milk  has  been  carefully 
studied  by  the  Dairy  Division  of  the  U.  S.  Department  of  Agriculture. 
Figures  as  to  the  number  of  men  employed  and  as  to  time  taken  to  bottle 
the  milk  were  obtained  from  the  plant  managers  and  these  were  checked 
up  by  observations  in  the  plants.  The  figures  do  not  include  the  packing 
of  the  milk  in  the  storage  room  after  the  milk  was  bottled.  These  four 
methods  of  bottling  were  considered : 


THE  MILK  CONTRACTOR 


319 


1.  By  large  automatic  machines  that  fill  and  cap  the  bottles  in  the  case,  a  full  case 
at  a  time. 

2.  Rotary  types  of  fillers  and  cappers  that  work  automatically  but  in  which  the 
bottles  are  filled  and  capped  out  of  their  cases  and  afterwards  returned  to  them. 

3.  Machines  that  fill  and  cap  the  bottles  in  the  case  but  that  are  operated  by  hand 
levers  instead  of  automatically.     Many  of  these  machines  fill  a  case  of  pint  bottles  at 
one  end  and  a  case  of  quarts  at  the  other. 

4.  Machines  that  fill  the  bottles  as  in  the  third  method  but  leave  the  capping  to  be 
done  by  hand. 

The  method  of  both  filling  and  capping  by, hand  was  not  studied. 

In  figuring  costs,  the  labor,  cost  was  obtained  by  dividing  the  total 
amount  expended  for  labor  at  all  the  plants  by  the  total  number  of  bot- 
tles that  were  filled  and  capped  at  the  same  number  of  plants.  The 
number  of  bottles  filled  and  capped  per  man  per  hour  was  determined  by 
dividing  the  total  number  of  bottles  filled  at  all  the  plants  by  the  total 
number  of  men-hours  used  at  the  same  number  of  plants.  The  results 
are  shown  in  Table  89. 

TABLE  89. — THE  COMPARATIVE  COST  OF  FILLING  MILK  BOTTLES  AND  CAPPING  THEM 
WITH  DIFFERENT  TYPES  OF  MACHINES  (U.  S.  DEPARTMENT  OF  AGRICULTURE) 


Method 

Number 
of 
plants 

Number 
of 
cities 

Number  of 
bottles 
filled  per 
hour 

Number  of 
bottles 
filled  per 
man 
per  hour 

Labor  cost, 
cents  per 
100 
bottles 

Range  in 
cost 
(cents) 

Large  automatic  

13 

4 

2,771 

1,233 

1.6 

0.9-2.3 

Rotary  automatic  
Non-automatic  machine  filler 

17 
17 

\ 

2,523 
3,635 

788 
830 

2.3 
2.6 

1.8-3.4 
1.3-5.3 

Machine  filler,  hand  capping 

60 

5 

1,798 

553 

3.4 

1.7-8.0 

The  table  shows  that  there  is  considerable  variation  in  labor  costs  at 
the  different  plants  using  the  same  types  of  -machinery.  The  cost  of  hand 
capping,  on  the  average,  was  much  higher  than  machine  capping  but  in 
some  cases  the  labor  cost  of  capping  the  bottles  by  hand  was  nearly  as 
cheap  as  by  machine.  In  plants  where  capping  is  done  by  hand  the  grade 
of  labor  employed  largely  influences  the  cost;  some  men  can  cap  bottles 
nearly  as  fast  as  the  machine  fills  them  while  others  cannot.  The  average 
cost  with  the  rotary  fillers  is  somewhat  less  than  with  the  machine  fillers 
and  the  variation  in  cost  at  the  different  plants  is  less  but  the  bottom  price 
of  machine  filling  is  less  than  that  of  rotary  filling.  In  explanation  of 
these  facts  it  is  offered  that  in  the  plants  using  the  rotary  fillers,  wages 
were  lower  than  in  plants  using  the  machine  fillers;  the  rotaries  were  of 
about  the  same  type  and  capacity  whereas  the  machine  fillers  differed 
greatly  in  these  respects.  Had  all  the  stationary  fillers  been  of  the  most 
efficient  type  and  had  they  been  run  in  the  best  possible  manner  the 
costs  would  have  been  materially  less  than  shown  in  the  table.  Instan- 
ces were  found  where  the  costs  with  the  machine  fillers  were  less  than  were 


320 


CITY  MILK  SUPPLY 


shown  by  any  of  the  rotaries.  Many  other  factors  besides  the  efficiency 
of  the  operators  and  the  types  of  the  machines  are  important  elements  in 
the  final  cost  of  bottling;  thus  in  some  plants  dirty  and  broken  bottles 
delayed  the  machines  while  in  others  the  pasteurizers  did  not  deliver  the 
milk  fast  enough  to  admit  of  the  fillers  being  run  to  capacity. 

In  all,  107  plants  in  six  cities  were  studied.  It  was  found  that  the 
average  number  of  bottles  filled  and  capped  per  hour  was  3,236,  or  per 
man  per  hour  839  and  that  the  labor  cost  ranged  from  0.9  to  8  cts.  per 
100  bottles  and  averaged  2.4  cts.  Table  90  shows  how  the  costs  varied 
in  the  six  cities. 

TABLE  90. — COST  OP  FILLING  AND  CAPPING  MILK  BOTTLES  IN  Six  PRINCIPAL  CITIES  OF 
THE  UNITED  STATES  (U.  S.  DEPARTMENT  OP  AGRICULTURE) 


City 

Number  of 
plants 

Labor  costs 
in  cents 

Variations  in 
cents 

Number  of 
bottles  per 
man  per  hour 

Philadelphia 

25 

1  8 

0.9-5.3 

1,086 

New  York  '  

3 

2.1 

1.9-3.3 

964 

Pittsburgh  

8 

2.2 

1.5-6.3 

937 

Baltimore 

16 

2.1 

1.3-6.7 

739 

Boston 

32 

3  1 

1  9-8  0 

725 

Washington,  .  .  

23 

3.3 

1.8-5.5 

571 

According  to  these  figures  the  average  costs  in  Boston  and  Washington 
were  higher  than  in  the  other  cities,  but  in  Washington  a  larger  proportion 
of  the  smaller  and  less  efficient  plants  were  studied,  while  in  Boston  26 
of  the  plants  that  supplied  data  were  capping  by  hand  at  a  cost  of  from 
2.1  to  8  cts.  per  100  bottles  and  at  an  average  cost  of  4.5  cts.  The  wages 
in  Boston,  too,  were  higher  than  in  some  of  the  other  cities.  More  auto- 
matic machines  were  used  in  Philadelphia,  New  York  and  Baltimore 
than  in  other  cities. 

The  rates  at  which  bottles  were  handled  by  the  different  machines 
are  shown  in  Table  91. 


TABLE  91. — RATE  PER  HOUR  AND  PER  MAN  PER  HOUR  AT  WHICH  DIFFERENT  TYPES 
OF  MACHINES  FILLED  AND  CAPPED  MILK  BOTTLES   (U.  S.   DEPARTMENT  OF 

AGRICULTURE) 


Type  of  machine 

Bottles  filled  and 
capped  per  hour 

Bottles  filled  and 
capped  per  man 
per  hour 

Large  automatic  machine,  filling  and  capping  a  full 
case  at  a  time.  . 

1,938-8,622 

966-2,155 

Rotary-type  filler  and  capper  
Machine  filler  and  capper.  .                                    

1,350-2,446 
750-7,760 

587-1,040 
375-1,552 

Hand  capping  

350-5,000 

238-1,066 

THE  MILK  CONTRACTOR 


321 


It  thus  appears  that  in  plants  using  the  same  type  of  machinery  there 
is  a  wide  variation  in  the  amount  of  work  done.  It  is  evident,  too,  that 
there  is  a  wider  variation  in  the  number  of  bottles  filled  per  hour  than  in 
the  number  filled  per  man  per  hour.  This  is  partly  explainable  by  the 
fact  that  in  some  plants  more  men  than  necessary  were  working  on  the 
machines. 

Taking  into  account  the  overhead  charges,  interest  being  figured  at 
5  per  cent,  and  depreciation  of  the  machinery  at  20  per  cent.,  the  compara- 
tive economy  of  the  different  types  of  machines  is  shown  by  the  U.  S. 
Department  of  Agriculture  in  the  graph  (Fig.  44). 


0.0002 
0.0001 


Number  of  Bottles 

FIG.  44. — Curves  showing  the  labor  and  overhead  costs  of  filling  and  capping  by  dif- 
ferent methods  at  various-sized  plants. 

(Milk  Plant  Letter  No.  41,  Dairy  Div.,  U.  S.  Dept.  of  Agriculture.) 

The  cost  of  the  automatic  fillers  was  taken  at  12,500,  of  the  rotaries  at 
$800,  of  the  machine  fillers  and  cappers  at  $1,200,  and  that  of  the  fillers 
where  capping  was  done  by  hand  at  $250.  Taking  the  wage  at  20  cts.  an 
hour  the  average  labor  costs  are  computed  for  each  type  of  machine  by 
dividing  this  amount  by  the  number  of  bottles  filled  and  capped  per  man 
per  hour  which  shows  a  cost  of  0.016  ct.  for  the  automatic  machines,  0.025 
ct.  for  the  rotaries,  0.024  ct.  for  the  machine  fillers  and  cappers  and  0.036 
ct.  for  the  hand  capping.  Reference  to  Fig.  44  shows  that  the  curve 
representing  the  rotaries  intersects  the  hand-capping  curve  at  3,400  which 
indicates  that  in  plants  handling  less  than  that  number  of  bottles  the 
hand-capping  system  would  be  the  more  economical.  The  rotary  curve 
21 


322 


CITY  MILK  SUPPLY 


cuts  that  representing  the  automatic  machines  at  13,000  thus  signifying 
that  in  plants  handling  from  3,400  to  13,000  bottles  the  rotaries  are  more 
suitable  than  the  automatic  machines.  The  filling  and  capping  machine 
curve  crosses  the  hand-capping  curve  at  5,500,  the  automatic  at  11,000 
and  the  rotary  at  27,000  and  so  indicates  the  field  that  the  filling  and  cap- 
ping machines  can  profitably  occupy.  These  suppositions  cannot  be  laid 
down  as  rules  because  other  factors  than  those  considered  affect  the  costs. 
In  these  estimates  the  cost  of  power  to  run  the  automatic  machines  was 
not  included  and  definite  figures  as  to  the  depreciation  of  the  rotary 
machines  were  not  available  since  they  have  but  recently  been  put  into 
service.  The  number  of  machines  in  use  at  a  plant  affects  the  cost. 
Thus,  with  one  method  of  filling  and  capping,  in  10  plants  using  one 
machine  766  bottles  were  handled  per  man  per  hour,  while  the  number 
at  five  plants  using  two  machines  was  904  and  at  two  plants  using  three 
machines  was  but  629.  The  chief  reasons  for  this  are:  that  often  two  ma- 
chines were  operated  with  one  man  less  than  twice  the  number  necessary 
to  operate  one  machine,  thus  reducing  the  operating  cost;  when  three 
machines  were  used,  one  was  often  idle  because  a  great  deal  of  the  time 
not  enough  milk  was  handled  to  keep  more  than  two  machines  busy. 

The  number  of  men  used  at  different  plants  with  each  type  of  machine 
is  shown  in  Table  92. 

TABLE  92. — NUMBER  OP  MEN  USED  IN  OPERATING  DIFFERENT  TYPES  OF  FILLING 
AND  CAPPING  MACHINES  (U.  S.  DEPARTMENT  OF  AGRICULTURE) 


Type 

Number 
of  plants 

Average 
number  of 
men 

Variations 

Large  automatic  machines  

12 

4  3 

2-7 

(One  machine 

10 

2  8 

2-5 

Two  machines  

5 

4  4 

4-5 

Three  machines    .  .  . 

2 

8  0 

Machine  filler  and  capper 

17 

4  6 

3-8 

Hand  capping.  . 

60 

3  0 

1-6 

Bottle  Cases. — As  soon  as  the  bottles  are  filled  and  capped  they  are 
put  in  the  cold  room,  being  sent  thither  in  the  larger  plants  over  roller 
conveyors  and  in  the  smaller  ones  by  trucks.  The  cases  or  crates  that 
hold  the  bottles,  like  other  dairy  implements,  have  been  improved.  The 
first  were  entirely  of  wood  and,  while  they  had  the  advantage  of  being 
light,  were  not  easily  cleaned  and  being  absorptive  soon  became  smelly; 
moreover,  they  wore  out  quickly.  Substituting  removable  metal  par- 
titions for  the  wooden  ones  was  an  improvement  but  these  crates  gave 
place  to  those  made  entirely  of  galvanized  iron.  They  were  more  dur- 
able and  more  easily  kept  clean  and  free  from  odor  but  they  were  much 
heavier.  Furthermore,  metal  is  a  good  conductor  of  heat  and  cold,  so 


THE  MILK  CONTRACTOR  323 

that  in  summer  the  ice  in  which  the  bottles  were  packed  for  delivery 
melted  rapidly,  while  in  winter  bottles  were  likely  to  freeze  in  the  case  and 
break.  Also,  the  cases  became  bent  out  of  shape  and  so  would  not  center 
the  bottles  beneath  the  filling  machines.  The  case  that  has  been  finally 
evolved  is  a  metal  one  with  wire  bottoms  and  partitions;  such  cases 
keep  their  shape,  stand  hard  use,  and,  as  stacked,  tend  to  hold  the  air 
motionless  around  the  bottle,  so  that  at  all  seasons  of  the  year  they 
hold  the  temperature  of  the  milk  for  some  time,  at  that  at  which  it  is 
loaded  onto  the  delivery  wagons.  For  shipping  certified  milk,  refrigera- 
tor cases  are  used. 

Bottle  Caps. — Milk-bottle  caps,  except  the  metal  ones,  are  made  of 
sulphite  fiber  impregnated  with  paraffine.  The  paraffine  is  applied  hot 
and  should  be  put  on  the  cap  after  it  is  cut  and  printed  in  order  that  the 
edges  as  well  as  the  surfaces  may  be  coated.  If  a  good  grade  of  paraffine 
is  not  used  on  the  cap,  or  if  it  is  poorly  coated,  the  cap  will  impart  a 
noticeable  flavor  to  the  milk.  The  cheap  thinly  coated  caps  are  not 
waterproof  and  so  become  soft  and  spongy  from  absorbed  moisture.  As 
the  paraffine  is  hot  when  applied  to  the  caps  they  are  sterile  or  nearly 
so  when  first  made;  therefore,  the  problem  is  to  keep  them  sterile  till 
used.  Some  dealers  pack  them  in  rolls  by  machine  so  that  no  one  handles 
them,  but  others  are  not  so  careful.  Inspectors  do  well  to  assure  them- 
selves that  dairymen  are  storing  their  caps  in  a  clean  place  and  are  hand- 
ling them  properly. 

Common-sense  caps  are  not  easily  removed  from  the  bottle  and  so 
various  devices  have  been  brought  out  to  make  them  so.  One  firm  has 
a  little  projection  at  the  edge  by  which  the  cap  can  be  lifted.  It  prevents 
the  cap  from  setting  snugly  on  the  seat  and  so  admits  dirt  to  the  bottle. 
Another  cap  has  a  tab  affixed  to  the  top  by  a  wire  staple  which  sometimes 
rusts  and  discolors  the  milk.  One  cap  is  scored  across  the  middle  with 
the  intention  of  making  it  possible  to  raise  one  side  of  the  cap  to  pour 
out  the  milk  and  afterward  bend  the  cap  back  into  place.  The  printing 
of  the  cap  is  important ;  the  design  should  be  attractive  and  the  lettering 
distinct.  The  tendency  is  to  make  the  caps  gaudy  and  to  crowd  the 
words  together  so  that  they  carry  no  message.  By  putting  a  trade  mark, 
or  the  name  of  the  dairy,  or  a  pat  phrase  descriptive  of  the  milk  on  the 
cap  the  attention  and  trade  of  the  public  is  often  caught.  The  date  of 
bottling  is  stamped  on  the  cap  by  dealers  in  certified  milk  and  by  some 
others.  In  cities  where  the  milk  is  graded  the  grade  of  the  milk  is 
stamped  on  the  cap  in  large  letters. 

Milk  Bottles. — The  proper  and  economical  handling  of  glass  bottles 
is  an  important  element  in  the  city  milk  business.  Ever  since  Soxhlet's 
first  experiments  in  sterilizing  milk  they  have  been  used  more  or  less  as 
containers  for  it.  Pediatrists  and  those  interested  in  child  welfare  work, 
by  distributing  pasteurized  and  modified  milk  in  glass  bottles  somewhat 


324  CITY  MILK  SUPPLY 

increased  their  use,  but  the  idea  of  the  commercial  delivery  of  milk  in 
glass  vessels  seems  to  have  originated  with  Alexander  Campbell  and  he 
was  the  first  to  put  it  into  practice.  By  letter,  he  states  that  he  began 
the  delivery  of  milk  in  glass  bottles  in  the  City  of  Brooklyn,  now  Brook- 
lyn Borough,  New  York  City,  in  1878.  The  company  was  operated 
under  the  name  of  the  New  York  Dairy  Co.,  Ltd.  and  at  Monroe, 
Orange  County,  N.  Y.,  built  the  first  creamery  erected  in  the  United 
States  for  the  bottling  of  milk. 

The  first  bottles  used  were  designed  by  Mr.  Campbell  after  the  fashion 
of  beer  bottles  then  in  use  but  had  the  same  size  mouth  of  the  milk  bottles 
of  today  and  also  " lightning"  or  tin  tops  with  a  paper  beneath  the  tin  to 
prevent  leakage.  These  first  bottles  were  made  by  Henry  S.  Putnam  of 
New  York  City,  who  at  Mr.  Campbell's  suggestion,  for  the  purpose, 
modified  the  machinery  he  was  using  in  making  beer  bottles.  These 
bottles  cost  $21  a  gross  which  is  over  four  times  what  they  would  cost  now. 

In  December,  1879,  Dr.  J.  C.  Morris  of  Philadelphia  read  a  paper 
before  the  Franklin  Institute  of  that  city  recounting  his  success  in  deliver- 
ing milk  for  the  preceding  6  months  in  Cohansey  glass  jars.  He  alludes 
to  a  jar  in  use  by  a  Mr.  Lester  and  criticises  those  in  use  by  Mr.  Starr  of 
New  York  and  M.  D'Arcy  of  Paris.  Mr.  Lester  was  of  Brooklyn  and 
attempted  to  introduce  1-  and  2-qt.  jars  that  had  a  metal  fixture  with  a 
rubber  gasket  and  a  thumb-screw  on  top  to  hold  on  the  glass  cover  but 
the  device  was  never  a  success.  Mr.  F.  R.  Starr  was  also  of  Brooklyn 
and  established  a  Jersey  herd  at  his  Echo  Farm  Dairy  in  Litchfield,  Conn. 
He  delivered  milk  in  glass  bottles  in  New  York  City  in  the  latter  part  of 
1879  or  the  beginning  of  1880.  Later  his  company  was  absorbed  by 
Mr.  Campbell's.  Dr.  H.  S.  Thatcher  patented  a  milk  bottle  in  1883 
that  was  first  used  by  Mr.  Wilcox  in  Ogdensburg,  St.  Lawrence  County, 
N.  Y.,  in  that  same  year.  Milk  was  first  delivered  in  glass  bottles  in 
Boston,  Mass.,  by  C.  L.  Alden,  then  of  the  Forest  View  Farm  of  Westwood, 
Mass.,  but  now  of  the  Oak  Grove  Dairy  of  Boston,  who  in  the  fall  of  1884 
started  bottle  service  in  Hyde  Park  and  in  1883  in  West  Roxbury,  a  part 
of  Boston.  In  1886  the  Whitman  Dairy  began  delivering  milk  in  glass 
bottles  in  New  York  City.  In  1889  under  a  single  letters  patent  the 
Thatcher  Manufacturing  Co.  patented  the  "  common-sense "  milk  bottle 
and  the  "  common-sense  "  cap. 

At  first  there  was  vigorous  opposition  to  the  use  of  glass  containers. 
On  the  one  hand,  it  was  an  innovation  to  customers  and  on  the  other, 
dealers  predicted  that  breakage  would  be  so  great  that  the  expense  would 
'be  prohibitive.  Mr.  Stephen  Francesco  once  told  the  writer  that  when 
he  began  the  use  of  glass  bottles  his  customers  said  they  did  not  want  milk 
from  the  drug  store.  Nevertheless  the  bottles  slowly  won  their  way.  By 
1896  approximately  10  per  cent,  of  the  milk  of  Philadelphia  was  delivered 
in  glass  bottles.  About  1895  the  delivery  of  milk  in  glass  bottles  was 


THE  MILK  CONTRACTOR  325 

begun  in  Chicago.  In  1896  it  was  begun  in  Cincinnati  and  in  1907  was 
made  compulsory  there.  Nowadays  only  small  towns  have  any  consider- 
able part  of  the  household  deliveries  made  otherwise  than  in  glass  bottles. 
Milk  bottles  should  be  made  of  the  best  clear  flint  glass  and  should  be 
properly  annealed,  otherwise  they  will  be  brittle  and  will  fail  to  stand 
rough  usage  and  the  violent  changes  in  temperature  to  which  they  are 
subjected  in  washing  and  sterilizing.  They  should  be  free  from  flaws 
and  the  glass  should  be  evenly  distributed ;  irregularities  are  most  likely 
to  occur  on  the  shoulder  and  at  the  mouth.  Most  of  the  breakage  is  due 
to  the  poor  annealing  and  to  uneven  distribution  of  the  glass.  The  cap- 
seat  should  be  carefully  formed  and  both  it  and  the  bottle  mouth  should  be 
finished  smooth  that  cleaning  brushes  may  not  be  cut  on  sharp  edges.  The 
bottles  of  different  makers  vary  somewhat  in  size  but  the  %-pt.  is  approxi- 
mately 5J4  by  2%  in.,  the  pint  1%  by  3^  in.,  and  the  quart  9%  by  3% 
in.  It  is  highly  important  that  the  capacity  of  the  bottles  be  guaranteed; 
usually  it  is  specified  that  they  shall  hold  not  over  2  cubic  centimeters 
above  nor  less  than  2  cubic  centimeters  below  the  indicated  capacity.  Of 
course,  if  the  bottles  hold  more  than  represented  it  means  loss  to  the  dairy- 
men while  if  they  contain  less  it  means  loss  to  the  consumer,  and  is  likely 
to  land  the  dealer  in  court,  for  the  milk  codes  of  many  cities  forbid  the  use 
of  undersized  bottles.  The  weight  of  milk  bottles  varies  but  in  those  of 
good  quality  the  ^  pt.  weighs  about  80  Ib.  per  gross,  the  M-pt-  125,  the 
pint  180,  and  the  quart  280.  There  is  considerable  diversity  in  the  shape 
of  the  bottles  apart  from  the  special  models  adopted  by  some  dairymen  as 
advertisements  and  also  as  obstacles  to  their  use  by  others.  Manu- 
facturers properly  endeavor  to  fashion  bottles  so  that  they  will  show  up 
the  cream  well  but  there  are  on  the  market  bottles  with  long  narrow 
necks  that  give  the  consumer  an  entirely  false  impression  of  the  amount 
of  cream  his  milk  carries.  Besides  the  common-sense  bottles  there  are 
those  with  small  mouths  and  no  cap-seats,  that  are  for  caps  that  entirely 
cover  the  tops.  All  bottles  should  be  of  a  shape  convenient  to  clean. 
Many  dairymen  use  plain  bottles  but  it  is  better  for  the  owner  to  have 
his  name  or  that  of  the  dairy  or  some  distinctive  mark  moulded  into  the 
glass  for  it  enables  him  to  prove  his  property  and  should  discourage 
others  from  using  it.  In  some  cities  the  law  forbids  one  dairyman  using 
another's  bottles.  Such  laws  protect  the  dairyman  in  the  right  to  his 
property  and  are  some  defense  from  the  danger  of  his  unwittingly  coming 
into  possession  of  and  using  those  of  his  bottles  that  other  dairymen  have 
placed  in  houses  harboring  communicable  disease.  Discretion  should  be 
used  in  enforcing  such  laws  for  much  of  the  delivery  of  milk  is  done  in  the 
dark  and  men  of  honest  intention  will  at  times  get  hold  of  bottles  that  do 
not  belong  to  them.  Milk  bottles  should  be  colorless  but  many  of  them 
are  not  so.  Some  have  a  purple  hue  because  the  glass,  which  had  no  color 
when  the  bottles  were  new,  contains  manganese  which  the  sunlight  con- 


326  CITY  MILK  SUPPLY 

verts  to  an  oxide  that  tints  the  glass.  Other  glass  contains  iron  which 
imparts  a  greenish  cast  to  the  glass,  making  the  milk  look  as  though  it 
was  skimmed.  Some  manufacturers  purposely  give  the  glass  a  yellow 
hue  to  deceive  customers  into  the  belief  that  they  are  receiving  very  rich 
milk.  Colorless  bottles  clean  up  brighter  than  those  with  a  shade  of 
color.  Some  bottles  remain  in  service  long  enough  to  become  disfigured 
with  scratches,  chipped  or  nicked  and  leaky  around  the  mouth.  Such 
bottles  should  be  discarded  because  they  make  a  bad  impression  on  cus- 
tomers and  because  a  leaky  milk  bottle  is  one  that  can  be  contaminated. 
The  greatest  care  should  be  taken  that  slivers  of  glass  do  not  get  into  the 
bottles  of  milk.  The  breakage  and  loss  of  bottles  imposes  a  heavy  tax  on 
the  milk  business. 

Breakage  and  Misuse  of  Milk  Bottles. — From  replies  by  40  dealers 
the  U.  S.  Department  of  Agriculture  found  out  that  a  milk  bottle  lasts 
from  6  to  60  trips,  the  average  being  22.5.     So  with  a  dealer  who  delivers 
10,000  bottles  daily,  if  the  cost  was  3J^  cts.  apiece  and  if  he  had  to  replace 
them  every  22.5  days,  the  daily  expense  for  bottles  would  be  $15.55  or 
$5,675.75  a  year.     In  so  far  as  this  loss  is  due  to  breakage  it  is  unavoid- 
able but  a  great  part  of  it,  perhaps  the  largest  part,  should  rightfully  be 
charged  to  the  extravagant  and  dishonest  habits  of  the  American  people. 
Bottles  instead  of  being  returned  to  the  dealer  are  thrown  into  the  ash 
barrel  or  wilfully  broken  or  are  converted  by  housewives  to  their  own  use 
for  such  purposes  as  holding  preserves,  groceries,  etc.     Part  of  the  trouble 
comes  from  the  trade  in  milk  in  stores  for  the  purchaser  although  he  may 
have  had  to  make  a  deposit  for  the  bottle,  never  finds  it  convenient  to 
carry  it  back  or  a  surly  storekeeper  may  make  refunds  for  the  bottles  so 
ungraciously  that  people  are  deterred  from  asking  for  them.     In  many 
of  the  larger  cities,  milk-bottle  exchanges  which  are  usually  operated  by 
dairymen  who  are  the  stockholders  in  the  concern  have  been  established 
to  reduce  the  loss  from  strayed  and  stolen  bottles.     Employees  of  the 
exchange  collect,  carry  to  its  plant  and  clean  the  bottles  which  the  several 
dealers  have  accumulated  that  do  not  belong  to  them  and  that  pickers  at 
the  public  dump  have  saved.     Junk  dealers  sell  the  bottles  they  have 
collected  to  the  exchange  and  some  exchanges  purchase  bottles  from  those 
dealers  who  go  to  the  trouble  and  expense  of  bringing  in  the  stray  bottles 
they  have  gathered  up.     Usually  nothing  is  paid  for  bottles  collected  at 
the  dealer's  plants  but  bottles  brought  to  the  exchange  are  generally 
paid  for  at  the  rate  of  Y±  to  J^  ct.  apiece.     The  number  of  bottles  re- 
covered from  the  public  dump  is  astounding;  the  records  of  one  exchange 
show  that  in  the  city  in  which  it  operated,  from  this  source,  1,500,000 
bottles  were  recovered  in  3  years.     Thus  we  gaily  indulge  in  the  cost  of 
high  living. 

Besides  being  depleted  by  thievery  and  breakage,  a  dealer's  stock 
of  bottles  suffers  from  abuse.     Milk  bottles  are  converted  to  containers 


THE  MILK  CONTRACTOR 


327 


for  every  conceivable  substance  from  paints,  oil  and  varnish  to  dyes,  urine 
samples  and  anatomical  specimens.  Of  course  some  such  bottles  are  un- 
cleanable  while  others  are  so  with  difficulty  and  at  added  expense.  In 
some  cities  it  is  a  misdemeanor  to  fill  a  bottle  with  another  substance 
than  milk  and  the  code  makes  it  incumbent  on  the  customers  to  wash 
milk  bottles  before  returning  them  to  the  dealer.  To  protect  the  milk 
dealer  in  the  sole  use  of  his  containers  a  law  has  recently  been  enacted 
in  New  York  State  permitting  the  owner  to  place  his  mark  upon  his  milk 
cans,  jars,  bottles  and  register  it  with  the  Commissioner  of  Agriculture. 
The  possession  of  these  containers  by  another  is  held  presumptive  evidence 
of  the  violation  of  the  law. 

Paper  Bottles. — The  attempt  has  been  made  but  not  successfully  to 
introduce  paper  bottles.     The  chief  advantages  from  such  bottles  would 


Courtesylflf  Stephen  Francisco. 

FIG.  45. — Bottle  sterilizer  and  bottle-washing  machine  at  the  Fairfield  Dairy, 

Caldwell,  N.  J. 

come  from  the  fact  that  they  are  light  and  therefore  easy  to  handle,  that 
they  would  be  used  but  once  and,  so,  would  cut  out  the  drudgery  and 
expense  of  washing  and  the  breakage  bill.  Their  disadvantages  are  that 
they  are  expensive,  lack  strength  and  not  being  transparent  prevent  the 
customer  from  judging  of  their  cleanliness  and  of  that  of  their  contents 
and  from  observing  the  cream  line. 


328 


CITY  MILK  SUPPLY 


Bottle  Washing. — Bottles  are  washed  by  hand  in  the  small  dairies 
and  by  machines  in  the  larger  ones.  In  hand  washing  the  bottle  is  merely 
swabbed  out  with  a  brush  and  the  bottles  rinsed  in  a  tank;  in  somewhat 
larger  dairies  the  bottles  are  washed  by  revolving,  power-driven  brushes 
and  rinsed  in  a  tank  or  quite  as  often,  over  small  jet  machines.  The 
largest  dairies  use  big  automatic  bottle  washers  that  wash  the  bottles 
in  their  cases.  The  machines  are  made  by  several  manufacturers  and 
of  course,  differ  from  one  another  in  construction  but  in  general  they  have 
a  soaking  tank  or  compartment,  a  washing  compartment  where  the  bottles 
are  cleaned  by  revolving  brushes  or  more  often  by  jets  of  hot  water  shot 
into  the  bottle  and  case  under  high  pressure,  a  rinsing  compartment  where 
jets  of  hotter  water  play  on  the  bottles  and  finally  a  sterilizing  compartment 
where  the  bottles  are  put  into  boiling  water,  or  have  either  jets  of  very 
hot  water  or  of  steam  played  on  them.  These  machines  wash  all  but  the 
exceedingly  dirty  "alley"  bottles  clean,  and  are  no  doubt  capable  of 
killing  all  of  the  non-spore-bearing  germs  if  run  at  the  temperature  directed 
by  their  makers  but  if  dairymen  economize  by  cutting  down  the  heat, 
these  washers  do  not  sterilize  the  bottles.  Inspectors  should  satisfy 
themselves  that  the  machines  are  operated  properly.  A  cold  washroom 
full  of  vapor  is  no  guarantee  that  the  sterilization  that  is  being  attempted 
by  steam  is  effective. 

Cost  of  Bottle  Washing.— The  Dairy  Division  of  the  U.  S.  Department 
of  Agriculture  has  made  a  study  of  the  cost  of  washing  bottles.  Data 

TABLE  93. — COST  OP  WASHING  MILK  BOTTLES  IN  91  PLANTS  BY  AUTOMATIC,  BY 
BRUSH  MACHINES  AND  BY  HAND  (U.  S.  DEPARTMENT  OF  AGRICULTURE) 


Method  of 
washing 

Number 
of 
plants 

Number 
of 
cities 

Labor  cost 
in  cents  per 
100  bottles 

Range  of 
cost,  cents 

Number  of 
bottles  washed 
per  man  per 
hour 

Number  of 
bottles  washed 
per  hour 

Automatic        ma- 
chines 

40 

5 

1   9 

07-42 

1  044 

4  196 

Brush  machines.  .  . 
Hand  

43 

8 

5 

4.9 
9.7 

2.1-  7.5 
6.4-13.2 

342 
199 

1,061 

433 

TABLE  94. — COMPARISON  OP  THE  COST  OF  WASHING  BOTTLES  IN  FIVE  CITIES  OF  THE 
UNITED  STATES  (U.  S.  DEPARTMENT  OF  AGRICULTURE) 


City 

Number  of 
plants 

Labor  cost 
in  cents  per 
100  bottles 

Range  of 
cost,  cents 

Number  of 
bottles  washed 
per  man  per 
hour 

Philadelphia,  Pa  
Baltimore,  Md  

20 
11 

1.8 

1.5 

1.0-  3.0 
0.7-  6.0 

1,115 
1,054 

Boston,  Mass. 

32 

3  1 

1  3-13  2 

691 

Pittsburgh,  Pa. 

9 

3  2 

27-75 

610 

Washington,  D.  C  

19 

4.3 

1.7-11.1 

377 

THE  MILK  CONTRACTOR 


329 


was  collected  in  91  milk  plants  in  Boston,  Baltimore,  Philadelphia,  Pitts- 
burgh, and  Washington.  Table  93  summarizes  the  cost  of  washing 
bottles  at  these  plants  and  Table  94  shows  how  the  cost  of  washing 
bottles  in  the  five  cities  compares,  all  three  types  of  washing  being  used. 

In  Table  94  the  results  were  obtained  by  dividing  the  total  cost 
of  labor  at  all  of  the  plants  in  each  city  by  the  whole  number  of  bot- 
tles washed  in  that  city.  The  high  costs  in  some  of  the  large  plants 
in  Washington  increased  the  average  cost. 

Table  95  summarizes  the  costs  for  all  the  plants  studied  in  the  five 
cities  and  Table  96  compares  the  bottles  washed  per  hour  and  per  man  per 
hour  by  the  three  methods. 

TABLE  95. — COST  OF  WASHING  BOTTLES  IN  91  PLANTS  IN  FIVE  CITIES  OP  THE  UNITED 
STATES  (U.  S.  DEPARTMENT  OF  AGRICULTURE) 


No.  of  plants 

Cost  in  cents  per 
100  bottles 

Range    of    cost, 
cents 

No.    of    bottles 
washed  per  man 
per  hour 

No.    of    bottles 
washed  per  hour 

91 

2.4 

0.8-13.2 

809 

2,870 

TABLE  96. — COMPARISON  OF  THE  NUMBER  OF  BOTTLES  WASHED  BY  THREE  DIFFER- 
ENT METHODS  (U.  S.  DEPARTMENT  OF  AGRICULTURE) 


Method 


No.  of  bottles  washed  per  man  per 


hour 

Hand  

180-950 

135-266 

Brush  machines  

233-3,840 

200-800 

Automatic  machines  

1,296-7,916 

525-2,000 

Table  96  shows  a  wide  variation  in  efficiency  even  when  the  same 
method  of  washing  is  used.  This  is  partly  accounted  for  by  various  fac- 
tors such  as  machines  of  the  same  type  being  more  serviceable  and  of 
larger  capacity  than  others,  operators  being  delayed  by  breakdowns, 
broken  bottles,  lack  of  steam,  etc.,  but  the  lower  figures,  as  a  whole,  show 
poor  work. 

Table  97  shows  the  number  of  men  employed  with  the  different  methods 
at  the  several  plants  studied. 

TABLE  97. — NUMBER  OF  MEN  EMPLOYED  ON  DIFFERENT  TYPES  OP  BOTTLE-WASHING 
MACHINES  (U.  S.  DEPARTMENT  OF  AGRICULTURE)  • 


Type 

No.  of  plants 

Average  No.  of  men 
used 

Range  in  No.  of  men 

Automatic  machines  
Brush  machines 

40 
43 

3.6 

2.8 

2-8 
1-7 

Hand 

8 

2.1 

1-5 

330 


CITY  MILK  SUPPLY 


From  the  labor  costs  and  the  cost  of  machinery  used,  the  relative 
economy  of  the  different  methods  of  washing  bottles  for  plants  of  different 
sizes  can  be  determined.  The  average  cost  of  brush  machines  was  $175 
and  of  automatic  washers  was  $1,500  with  a  20  per  cent,  depreciation 
and  with  5  per  cent,  interest  on  the  investment;  the  overhead  expense 
at  these  prices  is  12  cts.  per  day  for  the  brush  machine  and  $1.03  for  the 
automatic.  In  hand  washing  the  overhead  expense  would  be  the  upkeep 


Number  of  Bottles 

FIG.  46. — Curves  showing  the  labor  and  overhead  costs  of  washing  bottles  by  dif- 
ferent methods  at  plants  of  various  sizes. 

( Milk  Plant  Letter  No.  18,  Dairy  Div.,  U.  S.  Dept.  of  Agriculture.) 

of  the  floor  space  and  is  not  figured.  Taking  the  wage  at  20  cts.  an  hour 
the  labor  cost  with  each  type  is  determined  by  dividing  this  by  the  num- 
ber of  bottles  washed  per  man  per  hour  in  each  type  which  gives  0.00019, 
0.000585  and  0.00101  ct.  for  hand,  brush  and  automatic  washing  respect- 
ively. With  these  overhead  expenses  as  an  average  and  this  labor  cost 
for  each  method  the  graph  (Fig.  46)  has  been  constructed.  Hand  wash- 
ing is  represented  by  a  straight  line  since  the  labor  cost  remains  the  same 


THE  MILK  CONTRACTOR  331 

for  any  sized  plant,  no  equipment  is  required  and  the  overhead  expense 
is  not  considered.  It  appears  that  the  line  representing  brush  washing 
is  uniformly  below  that  for  hand  washing  while  the  automatic  machine 
is  shown  to  be  cheaper  than  the  latter  when  1,200  to  1,300  bottles  are 
washed.  The  lines  representing  the  automatic  and  the  brush- washing 
machines  intersect  at  2,300  bottles  indicating  that  with  this  number  of 
bottles  to  wash  a  dealer  would  do  well  to  install  an  automatic  machine. 
The  Division  points  out  that  comparatively  few  plants  were  covered  and 
that  the  amount  of  power  required  has  not  been  included  in  calculating 
these  costs. 

Storage  and  Inspection  of  Bottles. — In  small  dairies  the  washed  bot- 
tles are  kept  in  the  milk-handling  room.  In  the  larger  dairies  the  bottles 
are  carried  on  roller  conveyors  to  the  storage  room.  On  the  way  the  cases 
are  carefully  inspected  for  chipped  and  cracked  bottles  and  a  sharp  watch 
is  kept  for  such  bottles  while  the  empty  bottles  are  being  fed  into  the 
filling  machine. 

Sterilization  of  Bottles  by  Steam. — After  bottles  are  washed  they 
should  be  sterilized.  In  plants  large  enough  to  afford  a  stationary  boiler 
the  sterilization  is  done  either  in  streaming  steam  or  steam  under  pressure, 
usually  15  Ib.  for  15  min.  being  used.  When  the  steaming  is  done  con- 
scientiously it  is  efficacious  but  if  done  in  a  haphazard  way  the  bottles 
may  be  merely  warmed  up  to  the  incubating  temperature  and  conditions 
created  for  bacterial  multiplication. 

Sterilization  of  Utensils,  Etc.,  with  Washing  Powders. — The  great 
majority  of  dairymen  cannot  afford  steam.  So  it  would  be  advantageous 
if  a  cheap  safe  disinfectant  were  available  for  their  use.  Doane  defined 
a  good  creamery  disinfectant  as  one  that  is  odorless,  tasteless,  non- 
poisonous,  cheap  and  in  small  quantities  is  reasonably  effective,  and  that 
is  germicidal  to  non-spore-bearing  forms. "  He  quotes  the  work  of  others 
on  the  value  of  soaps  as  disinfectants  and  tested  the  disinfecting  power 
of  several  washing  powders. 

Experiments  with  one  or  two  soaps  indicated  that  in  5  per  cent,  solu- 
tion they  are  effective  germicides.  To  the  free  alkali,  the  disinfecting 
power  of  the  soap  is  partly  attributable  but  he  is  inclined  to  believe  that 
either  the  glycerin  or  salts  of  the  fatty  acids  of  the  soap  have  bactericidal 
properties.  Since  the  appearance  of  this  paper,  the  disinfecting  power 
of  soaps  has  been  questioned;  Pease  has  recently  stated  that  it  is  con- 
siderable when  the  water  is  hot. 

While  the  composition  of  the  washing  powders  with  which  Doane  ex- 
perimented is  a  trade  secret  analysis  showed  that  they  were  80  per  cent, 
soap  and  20  per  cent,  free  alkali — the  latter  being  caustic  soda.  In  ex- 
perimenting, his  procedure  was  to  make  a  dilution  0.1  to  0.5  c.c.  of  milk 
in  5  c.c.  of  sterilized  water.  Then  for  the  controls  a  measured  quantity 
of  the  dilution  was  put  in  another  5  c.c.  of  sterilized  water  and  measured 


332  CITY  MILK  SUPPLY 

quantities  of  this  were  added  to  each  of  two  tubes  of  lactose  agar  and 
plated.  For  the  test  sample  the  same  quantity  of  the  dilution  was  put 
into  5  c.c.  of  a  solution  of  a  weighed  quantity  of  washing  powder  and 
water,  either  at  room  temperature  or  130°F.,  and  added  to  the  lactose 
agar  at  stated  intervals.  At  first  1  gram  of  powder  to  300  of  water  was 
used  but  this  was  found  to  be  too  weak  and  so  it  was  used  in  the  propor- 
tion of  1  gram  to  150  of  water  which  is  at  the  rate  of  1  Ib.  of  powder  to 
a  little  more  than  17  gal.  of  water.  The  powders  cost  5  to  6  cts.  a  pound. 
Savogdram,  Gold  Dust  and  Pearline  were  tested  and  also  sal  soda  or 
washing  soda,  baking  soda  and  caustic  soda.  The  results  indicate  that 
Savogdram,  Gold  Dust,  Pearline  and  sal  soda,  in  the  proportion  of  1  part 
by  weight  to  150  parts  of  water  at  the  temperature  of  130°F.  and  with  an 
exposure  of  10  min.  exert  a  notable  disinfecting  action.  However,  the 
objection  is  made  to  sal  soda  that  it  deteriorates  so  rapidly  that  it  can 
be  kept  in  stock  only  in  small  quantities.  In  contact  with  the  air  it 
loses  its  water  of  crystallization  and  crumbles  to  a  white  powder  that 
actually  interferes  with  washing.  Baking  soda  which  is  often  recom- 
mended for  cleaning  nursing  bottles  has  none  of  the  properties  of  a  soap 
and  no  disinfecting  action  when  used  in  the  proportion  of  1  part  to  150 
of  water  and  only  a  slight  one  in  the  proportion  of  1  to  8.  It  is  suggested 
that  by  neutralizing  the  sour  smell  in  the  bottle  it  deceives  one  into  the 
belief  that  it  is  a  cleaner.  The  experiments  with  caustic  soda  indicate 
that  there  was  something  besides  the  20  per  cent,  of  free  alkali  in  the 
washing  powders  that  in  a  marked  degree  increased  their  antiseptic 
properties. 

Wyandotte  and  tri-sodium  phosphate  are  used  in  large  quantities  as 
bottle  cleansers  but  neither  of  these  were  tested  in  the  experiments. 

Doane  advises  that  in  creameries  washing  powders  be  used  in  a  hot 
solution  of  1  Ib.  to  25  gal.  The  floors  should  first  be  washed  with  hot 
water  and  then  with  the  hot  solution  which  should  be  allowed  to  dry  off, 
for  the  longer  it  remains  the  more  effectively  will  it  kill  germs  and  check 
odors.  Tinware  should  be  rinsed  with  cool  or  tepid  water,  then  washed 
in  hot  water  after  which  the  solution  of  washing  powder  should  be  added 
and  the  utensil  shaken  to  make  sure  that  the  solution  touches  every  part. 
So  the  whole  stock  should  be  treated  and  finally  after  5  or  10  min.  should 
be  rinsed  with  clean  water. 

Washing  powders  deteriorate;  so  they  should  not  be  purchased  in 
large  quantities. 

Sterilization  of  Bottles  with  Bleaching  Powder. — Whittaker  and 
Mohler  suggest  the  sterilization  of  milk  bottles  by  submerging  them  for 
20  min.  in  a  solution  of  calcium  hypochlorite  or  bleaching  powder  con- 
taining not  over  10  parts  per  million  of  available  chlorine  or  roughly  1  oz. 
of  powder  to  100  gal.  of  water.  In  their  experiments  they  obtained  a 
total  average  bacterial  efficiency  of  over  99.9  per  cent.  An  examination 


THE  MILK  CONTRACTOR  333 

of  the  bacterial  plates  of  two  dairies  showed  that  over  95  per  cent,  of  the 
surviving  organisms  were  spore  bearers.  The  use  of  hypochlorite  must 
be  confined  to  the  sterilization  of  bottles  for  it  attacks  tinware  rapidly. 
Bottles  that  have  been  put  in  hypochlorite  or  bleach,  as  it  is  called,  should 
be  carefully  rinsed  lest  its  unpleasant  odor  may  cling  to  the  bottles  and 
cause  complaint  on  the  part  of  customers.  How  generally  chloride  of 
lime  is  used  by  dairymen  the  writer  does  not  know  but  is  of  the  opinion 
that  it  is  comparatively  little.  It  is  not  at  all  impossible  that  in  the  future 
it  may  be  employed  more  commonly.  It  kills  the  non-spore-bearing 
germs,  which  includes  most  of  the  disease  germs;  consequently,  when 
health  officers  and  others  have  to  disinfect  bottles  that  have  been  exposed 
to  infection,  and  no  steam  is  available  to  do  it  with  the  " bleach"  is  the 
very  thing  for  the  purpose,  but  the  bottles  should  be  rinsed  first,  because 
the  bleach  will  exhaust  its  strength  on  milk  and  other  organic  matter  and 
so  lose  some  of  its  germicidal  power.  Also,  the  bleaching  powder  must 
be  fresh  because  it  deteriorates  rapidly  on  exposure  to  air.  During  the 
prevalence  of  foot-and-mouth  disease  in  Illinois  in  1915  some  of  the  certi- 
fied dairies  regularly  immersed  their  milk  bottles  and  crates  in  a  solution 
of  chloride  of  lime. 

Milk  Cans. — The  milk  cans  are  important  milk  utensils.  They  have  to 
be  strong  because  they  are  subjected  to  merciless  treatment.  They  are 
made  of  steel  and  are  heavily  plated .  All  j  oints  are  flooded  with  solder  that 
there  may  be  no  crannies  where  milk  curd  may  accumulate  and  germs  mul- 
tiply. The  weak  points  of  the  can  are  the  neck,  the  bottom  and  the  breast. 
The  neck  is  usually  double  and  should  be  reinforced  strongly  where  it 
joins  the  can  for  great  strain  comes  at  this  point  from  piling  the  cans  on 
top  of  one  another,  people  standing  on  the  tops,  etc.  The  breast  is  usu- 
ally protected  by  a  heavy  steel  hoop  that  is  soldered  onto  the  outside  of 
the  can  and  the  bottom  is  protected  in  the  same  way  or  by  a  piece  of 
sheet  steel  rolled  over  the  body  in  such  a  way  as  to  make  a  projecting 
bottom  rim.  The  body  of  the  can  is  stamped  out  of  a  single  piece  of 
«teel.  The  covers  are  of  two  principal  types,  the  slip  cover  which  is  the 
commoner  and  the  umbrella  cover  which  is  being  adopted  because  it 
overhangs  the  can  and  protects  the  top  from  dirt.  Covers  are  usually 
made  of  seamless  drawn  steel  and  should  be  smooth  and  strong.  In 
New  England  the  8^-  to  10-qt.  cans  have  a  handle  attached  to  the  neck 
and  breast;  the  necks  are  3^  in.  in  diameter  and  are  sometimes  closed 
with  a  tin  cover  but  almost  always  a  stopple  or  bung  of  maple  or  other 
hardwood  is  used.  These  stoppers  are  absorptive  and  for  that  reason 
are  objectionable -on  sanitary  grounds.  The  handles  of  both  covers  and 
cans  should  be  rounded  and  of  ample  size.  As  the  cans  are  constantly 
traveling  they  should  be  marked  with  the  owner's  name  or  his  trade 
mark.  The  most  permanent  way  of  marking  cans  is  to  emboss  the  name 
with  a  die  on  the  breast,  cylinder  or  neck;  less  expensively,  letters  or  a  name 


334 


CITY  MILK  SUPPLY 


plate  may  be  soldered  onto  the  can.  One  of  the  problems  in  shipping 
milk  is  to  make  sure  that  the  milk  is  not  tampered  with  in  transit.  So 
various  devices  have  been  patented  for  locking  the  cans.  The  lead  seal 
is  most  commonly  used. 

The  condition  of  the  cans  must  be  good;  battered  and  dented  cans 
are  objected  to  because  they  give  short  measure  and  also  because  they 
are  impossible  to  clean  and  are,  therefore,  insanitary.  The  shipping  of 
cream  in  rusty  cans  is  the  cause  of  the  fishy  odor  in  butter.  Boards 
of  health  confiscate  rusty  and  battered  cans  because  of  their  highly  in- 
sanitary character. 

The  washing  of  cans  in  many  dairies  is  very  carelessly  done.  This 
is  a  great  mistake  for  if  they  are  not  thoroughly  clean  and  sterile  they  will 
seed  the  milk  that  is  put  in  them  with  germs.  It  is  particularly  bad 
to  leave  a  little  milky  water  in  the  can  for  it  is  a  splendid  culture  medium 
for  germs.  When  cans  are  cleansed  they  should  be  scrubbed  outside  and 
in,  thoroughly  rinsed,  and  then  sterilized  with  steam,  after'this  they  should 
be  dried  out  with  a  hot  air  blast  or  inverted  and  dried  in  the  air,  after 
which  the  cover  should  be  put  on.  Swabbing  out  a  can  with  a  sour  rag 
as  it  is  often  done  is  not  washing  it.  In  the  milk  plant  and  on  the  farm 
the  cans  should  be  kept  inverted  or  covered  to  keep  out  rats,  mice  and 
flies. 

Item  of  Shrinkage  in  City  Milk  Plants. — The  shrinkage  and  waste 
of  milk  in  city  milk  plants  is  an  item  to  be  considered.  One  of  the  large 
dealers  of  the  country  who  makes  a  determined  effort  to  keep  this  loss 
at  minimum  gives  the  figures  in  Table  98  showing  the  percentage  of  loss 
at  his  plant  month  by  month  for  2)^  years. 

TABLE  98. — PERCENTAGE  OP  SHRINKAGE  IN  THE  TOTAL  VOLUME  OF  MILK  IN  PASSING 
THROUGH  A  LARGE  CITY  MILK  PLANT 


Year 

Jan. 

Feb. 

Mar. 

Apr. 

May 

June 

July 

Aug. 

Sept. 

Oct. 

Nov. 

Dee. 

1911 
1912 
1913 

2.10 
2.44 
2.73 

2.42 
2.58 
2.65 

2.12 
2.21 
2.45 

2.44 
2.57 
2.32 

2.41 
2.11 
2.18 

2.62 

2.27 

3.91 
2.79 

3.56 
2.56 

3.28 
2.82 

3.29 
3.07 

3.32 
3.01 

3.22 
3.05 

Average  .  . 

2.42 

2.55 

• 

2.26 

2.44 

2.23 

2.44 

3.35 

3.06 

3.05 

3.18 

3.16 

3.14 

The  Dairy  Division  of  the  U.  S.  Department  of  Agriculture  obtained 
estimates  of  the  daily  losses  of  milk  in  city  milk  plants  from  41  dealers 
and  found  that  they  ran  from  0.5  to  4  per  cent.,  averaging  2.15.  A  dealer 
who  handles  5,000  gal.  of  milk  a  day  and  loses  2.15  per  cent,  of  it,  in  the 
course  of  a  year  with  milk  at  30  cts.  a  gallon,  would  lose  $11,771.25,  a 
very  tidy  sum.  The  Division  points  out  that  there  is  a  certain  amount 
of  unavoidable  loss  in  transferring  milk  from  cans  to  bottles  and  in  the 


THE  MILK  CONTRACTOR  335 

processes  of  clarifying  and  pasteurizing  but  that  most  of  the  loss  is  properly 
placed  under  the  other  heads  in  the  following  list  of  losses  and  should  be 
eliminated : 

1.  Leaky  cans. 

2.  Dented  or  battered  cans. 

3.  Partially  filled  cans. 

4.  Careless  handling  of  the  cans  in  transferring  them  from  the  cars 
and  in  dumping  them. 

5.  Insufficient  draining  of  the  cans. 

6.  Leaky  or  battered  apparatus. 

7.  Fillers  in  disrepair — leaky  valves. 

8.  Losses  at  the  filler  from  poorly  adjusted  valves,  careless  handling, 
breakage  of  bottles,  etc. 

9.  Loss  arising  from  failure  to  remove  all  the  milk  from  pasteurizers, 
pipes,  pumps,  tanks  and  other  apparatus. 

10.  Mechanical  losses,  and  loss  by  evaporation  in  clarifying,  pasteur- 
izing and  cooling. 

Homogenized  Milk. — Many  city  milk  dealers,  besides  selling  whole 
milk  and  cream,  put  out  homogenized  milk  and  milk  beverages.  The 
former  is  a  comparatively  new  product.  According  to  Baldwin  the 
patents  on  the  first  machine  were  taken  out  by  Gaulin  in  1892,  but  the 
present  successful  type  was  not  perfected  till  1902.  Milk  and  other 
emulsions  are  homogenized  by  forcing  them  through  very  fine  openings 
under  pressure  of  about  3,000  Ib.  per  square  inch  with  the  result  that  the 
fat  globules  are  broken  up  into  fragments  so  minute  that  they  cannot  ag- 
glutinate and  cannot  rise  because,  as  Lindet  has  shown,  the  ascending 
force  of  the  fat  globules  in  milk  and  cream  is  proportional  to  the  cubes 
of  their  radii  and  so  when  the  diameters  become  less  than  1  or  2  microns 
milk  will  not  cream. 

Homogenized  cream  can  neither  be  whipped  nor  churned  to  butter. 
In  this  country  two  machines  are  in  common  use  for  homogenizing  milk, 
the  Gaulin  and  the  Progress  homogenizers.  In  the  Gaulin  machine  the 
milk  is  forced  by  single-acting  pumps  against  an  agate  valve  which  presses 
against  a  ground  seat  and  forces  the  milk  between  the  ground  surfaces  of 
the  valve  and  seat.  In  the  Progress  machine  the  milk  is  forced  by  single- 
acting  pumps  between  a  series  of  discs  with  ground  surfaces.  The  discs 
are  placed  flat  on  one  another,  are  held  together  by  a  rod  running  through 
the  center  and  are  enclosed  in  a  cylinder.  The  discs  are  pressed  against 
each  other  by  a  heavy  spiral  screw  which  regulates  the  pressure  to  which 
milk  is  subject.  The  milk  passes  from  the  center  to  the  periphery  of  the 
discs  of  which  there  are  two  types.  One  of  them  has  very  fine  grooves 
through  which  the  milk  shoots  against  a  hard  shoulder  and  the  other  has 
smooth  surfaces  with  narrow  area  of  contact.  Owing  to  the  high  pres- 
sure under  which  the  machines  work,  considerable  skill  is  needed  to  oper- 


336 


CITY  MILK  SUPPLY 


ate  them  for  if  it  is  not  done  correctly  the  homogenized  milk  will  have  a 
"burnt"  or  "metallic"  flavor  readily  detectable  by  those  who  are  familiar 
with  it. 

Baldwin  made  two  sets  of  measurements  of  the  fat  globules  in  samples 
of  homogenized  cream  from  two  different  machines  working  under  pres- 
sures of  from  700  to  4,000  Ib.  per  square  inch.  He  found  that  in  general 
the  degree  of  homogenization  is  increased  with  the  pressure  and  in  one 
of  the  machines  the  destruction  of  fat  globules  is  so  great  that  most  of 
them  lose  their  spherical  form  and  under  a  2-mm.  objective  look  like  a 
fine  amorphous  precipitate.  The  diameter  of  the  majority  of  fat  globules 
Baldwin  found  to  be  of  0.005  to  0.006  mm.  and  of  the  homogenized 
globules  0.001  to  0.002  mm.  The  experiments  are  given  in  Table  99. 

TABLE  99. — RELATIVE  NUMBER  OF  FAT  GLOBULES  OF  VARIOUS  SIZES  IN  NATURAL 

CREAM  AND  IN  CREAM  HOMOGENIZED  UNDER  VARIOUS  PRESSURES  (BALDWIN) 

Diameters  in  millimeters 


0.009 

0.007 

0.006 

0.005 

0.004 

0.003 

0.002 

0.001 

to 

to 

to 

to 

to 

to 

to 

to 

0.007 

0.006 

0.005 

0.004 

0.003 

0.002 

0.001 

0.0005 

Natural  cream  

Few 

Many 

Most 

Few 

Few 

Very 

few 

Homogenized  cream 

Machine  No.  1. 

1  000  Ib 

Very 

Few 

Many 

Many 

Most 

Very    few 

^*  j 
few 

2,000  Ib. 

Very 

Few 

Many 

Most 

Very  few 

*  v*»j 

few 

4,000  Ib  

Few 

Many 

Most 

Very  few 

Machine  No.  2. 

700  Ib 

Very 

Many 

Many 

Most 

Very  few 

Few 

2,000  Ib. 

Many 

Mostly 

granular 

3,500  Ib  

Very 

Few 

Many 

Mostly 

• 

few 

granular 

Homogenized  milk  is  used  to  some  extent  for  infant  feeding  and  for 
invalids,  and  mixtures  are  used,  too,  that  are  made  by  homogenizing  olive 
oil  or  other  fats  in  place  of  the  butterfat.  Some  milk  dealers  put  out  an 
homogenized  milk  or  cream  that  is  popular  with  their  customers  and 
takes  the  place  of  coffee  cream.  A  drawback  to  this  product  is  that  it 
sometimes  curdles  when  coffee  is  poured  onto  it.  If  ice-cream  manufact- 
urers did  not  purchase  and  store  large  quantities  of  butter  fat  when  milk 
is  plenty  they  would  not  have  it  for  making  ice  cream  at  seasons  when 
little  is  to  be  had.  They  have  two  ways  of  meeting  the  situation :  one  of 
them  is  to  freeze  large  quantities  of  sweet  cream  and  hold  it  in  cold  storage 


THE  MILK  CONTRACTOR  337 

till  it  is  needed,  when  it  is  melted  for  use,  and  the  other  is  to  hold  large 
quantities  of  sweet  butter  in  cold  storage  and  homogenize  it  with  skim- 
milk  or  milk  powder  as  it  is  needed.  The  success  of  homogenizing  for 
these  purposes  has  led  to  the  introduction  of  machines  called  emulsors 
which  emulsify  cream  products  in  such  a  way  that  the  fat  is  not  broken  up 
enough  to  prevent  cream  and  butter  being  again  separated.  Ice  cream 
made  from  homogenized  cream  is  believed  by  some  to  be  superior  because 
of  its  smooth  consistency. 

One  milk  dealer  is  reported  to  have  lost  much  of  his  trade  by  tricking 
his  customers  by  separating  his  milk  and  homogenizing  the  cream  sepa- 
rately and  then  returning  it  to  the  milk  where  it  formed  a  more  bulky 
cream  than  before,  which  deception  cost  him  heavily  when  at  last  it  was 
discovered.  Also,  it  is  possible  to  homogenize  other  fats  than  butter- 
fats  with  skim -milk  and  so  to  deceive  the  public.  Thus  while  homo- 
genizing may  be  misused  by  the  unscrupulous,  in  the  hands  of  honest 
men  it  has  its  proper  applications. 

Milk  Beverages. — Much  of  the  skim-milk  in  milk  plants  is  made  into 
milk  beverages  which  are  used  in  increasingly  large  quantities  by  the 
public. 

Recovery  and  Use  of  Casein. — In  the  smaller  milk  plants  there  may 
be  considerable  loss  from  skim-milk  for  often  the  only  way  of  disposing 
of  it  is  to  sell  it  to  the  farmers.  In  other  plants  the  casein  is  recovered 
in  the  following  manner;  2,500  Ib.  of  skim-milk  are  heated  to  120°F.  and 
11.5  Ib.  of  sulfuric  acid  of  a  specific  gravity  1.83  are  added,  care  being 
taken  to  dilute  the  acid  well  before  putting  in  the  skim-milk,  other- 
wise it  will  burn  and  discolor  the  curd.  As  the  acid  is  added  the 
skim-milk  is  stirred.  If  too  little  acid  is  added  a  soft  curd,  which 
does  not  press  well,  results.  The  curd  is  pressed,  after  which  it  is 
ground  and  then  dried  at  145°F.  If  the  temperature  rises  to  150°F.  the 
curd  burns.  The  dried  curd  is  then  shipped  to  large  manufacturers  of 
casein  products. 

Care  of  Milk  Plant  and  Creamery  Wastes. — The  care  of  the  wastes  of 
a  city  milk  plant  or  of  a  creamery  is  important.  If  they  are  permitted 
to  flow  out  on  the  ground,  a  nuisance  results.  Whenever  it  is  possible 
connections  should  be  made  to  the  public  sewer.  Where  this  cannot  be 
done  other  methods  of  sewage  disposal  must  be  adopted.  In  some  cases 
the  sewage  may  be  disposed  of  by  dilution,  that  is,  by  discharging  it  into  a 
running  stream.  Sometimes  local  or  State  laws  prohibit  such  a  practice 
and  sometimes  the  volume  of  the  stream  is  not  great  enough  to  dilute 
the  creamery  effluent  to  such  a  degree  that  no  nuisance  will  result.  This 
is  the  more  likely  to  be  the  case  from  the  fact  that  the  volume  of  waste  is 
likely  to  be  largest  when  that  of  the  stream  is  smallest.  In  such  cases 
recourse  must  be  had  to  sewage  treatment. 

Two  methods  have  been  found  applicable  to  creamery  wastes,  viz.: 


22 


338  CITY  MILK  SUPPLY 

(1)  digestion  in  the  septic  tank  followed  by  filtration;  and  (2)  treatment 
in  the  Imhoff  tank.  Creamery  sewage  differs  from  ordinary  sewage  in 
that  it  contains  considerable  fat  and  much  casein,  which  make  it  prone  to 
clog,  and  lactic  acid  which  in  tanks  has  a  tendency  to  restrain  bacterial 
decomposition.  Besides  the  butterfat  it  carries  also  the  machinery 
oil  so  that  it  is  well  to  interpose  a  grease  trap  on  the  pipe  line  between  the 
plant  and  tank  to  catch  this  fat  and  also  lumps  of  casein,  that  do  not  de- 
compose easily.  Where  a  tank  is  used,  waste  acid  should  be  kept  out  of 
the  sewage  because  it  interferes  with  bacterial  decomposition.  The  clear 
water  that  is  used  for  cooling  should  also  be  kept  out  of  the  sewage  partly 
because  it  is  cold  and,  therefore,  tends  to  retard  bacterial  action  but  chiefly 
because  it  greatly  increases  the  volume  of  the  sewage  to  be  handled  and 
so  increases  the  cost  of  treatment  by  making  larger  works  necessary. 

The  tanks  should  be  large  enough  to  hold  the  sewage  for  3  days  and 
should  be  provided  with  a  dosing  chamber  for  continuous  discharge  onto 
the  filter  beds  interferes  with  their  action.  Sometimes  the  addition  in 
the  dosing  chamber  of  chloride  of  lime  at  the  rate  of  1  to  5  Ib.  per  1,000 
gal.  is  advisable  an  hour  before  running  the  tank  effluent  onto  the  filter 
beds  for  in  this  way  foul  odors  are  checked. 

The  filter  beds  are  built  of  properly  selected  sand  or  crushed  stone  that 
is  underdrained  with  open  vitrified  tile.  The  surfaces  should  be  kept  clean 
and  when  they  become  clogged  the  beds  should  be  raked  lightly.  In 
time  the  upper  surface  of  the  sand  has  to  be  removed  and  replaced.  The 
effluent  of  the  filter  beds  may  be  disposed  of  by  running  it  into  a  stream, 
or  more  economically  by  subsurface  irrigation  through  open-joint  tile 
or  by  surface  irrigation. 

The  Imhoff  tank  is  constructed  and  operated  as  such  tanks  usually  are 
and  needs  no  special  description.  However,  it  should  be  noted  that  owing 
to  the  development  of  acid  fermentation  it  may  be  necessary  to  add  a 
small  quantity  of  lime  to  the  waste  in  the  tank.  If  a  highly  purified  efflu- 
ent is  desired  it  may  be  advisable  to  filter  the  effluent  from  the  Imhoff 
tank.  Otherwise,  it  can  be  discharged  into  a  stream  or  onto  land. 

Holding  Milk  at  Low  Temperature. — Dairymen  who  operate  their 
routes  from  the  farm  generally  hold  the  milk  till  it  is  wanted  for  delivery 
in  tanks  of  spring  or  of  well  water.  Such  water  as  it  issues  from  the 
ground  usually  has  a  temperature  of  between  50°  and  55°F.  so  that  ordi- 
narily by  its  use  milk  cannot  be  cooled  to  as  low  a  temperature  as  desirable, 
viz.,  45°F.  Somewhat  better  results  can  be  obtained  with  ice  water. 
Small  milk  plants  use  ice  bunkers  to  cool  their  storage  rooms  and  larger 
ones  use  the  gravity  brine  system.  The  big  plants  use  mechanical  re- 
frigeration generally  with  ammonia  as  the  refrigerant.  Refrigeration 
is  a  highly  important  part  of  the  milk  business  but  it  cannot  be  properly 
developed  in  detail  here.  Those  readers  who  are  interested  in  the  sub- 
ject are  referred  to  Bowen's  bulletin  on  the  subject. 


THE  MILK  CONTRACTOR  339 

Refrigeration  in  the  Home. — Milk  dealers  are  interested  not  only  in 
the  refrigeration  that  their  producers  and  they  themselves  use  but  they 
are  also  in  that  in  the  homes  of  their  customers  for  the  best  milk  will  spoil 
soon  after  delivery  unless  it  is  kept  cold. 

Williams  made  an  extensive  investigation  of  the  facilities  for  keeping 
perishable  foods  in  the  homes  of  Rochester,  N.  Y.,  and  found  that  they 
were  generally  preserved  in  a  cool  place  in  the  cellar,  in  living  rooms  or  in 
ice  boxes.  He  came  to  the  conclusion  that  in  one-half  of  the  homes  the 
cellar  and  pantry  were  relied  on  to  preserve  food  and  that  in  three-quarters 
of  the  homes  ice  was  taken  for  only  a  few  weeks  in  mid-summer.  He  stud- 
ied 243  refrigerators  and  found  that  only  103  maintained  a  temperature 
of  less  than  50°F. ;  the  other  143  had  higher  temperatures  and  were  worth- 
less for  preserving  food.  The  better  refrigerators  were  in  the  better 
homes  but  in  45  per  cent,  of  the  homes  of  this  class  the  refrigerators 
showed  temperatures  of  over  50°  while  in  the  homes  of  the  working  people 
over  70  per  cent.  did. 

Economy  in  the  Use  of  Steam. — One  of  the  items  of  expense  in  the 
city  milk  business  is  the  cost  of  cleaning  and  sterilizing  the  utensils  and 
with  the  larger  dealers  this  is  augmented  by  the  necessity  of  generating 
power  to  run  separators,  clarifiers,  filling  and  capping  machines,  pumps 
and  pasteurizing  machinery.  The  very  smallest  dealers  get  on  by  heating 
the  water  they  need  over  stoves  but  this  is  tedious  work,  consequently  only 
a  very  few  use  enough  water.  So,  boards  of  health  are  taking  the  ground 
that  a  gas  heater  or  a  steam  boiler  must  be  used.  Indeed,  all  dairymen 
who  are  conducting  a  business  of  any  considerable  size  have  steam  boilers 
and  the  larger  dealers  have  big  power  plants  with  steam  boilers,  steam 
engines,  gas  engines  and  dynamos.  It  is  apparent  that  the  chances  of 
incurring  loss  in  this  part  of  the  business  are  good.  Waste  of  fuel, 
lubricants  and  other  supplies  is  bound  to  occur  unless  guarded  against. 
Incompetent  operation  of  the  plant  is  likely  to  cause  rapid  depreciation 
of  the  machinery  and  excessive  repair  bills.  Losses  occur,  too,  from  poor 
layout  of  the  plant  and  from  failure  to  utilize  all  the  heat  or  power  in 
the  steam. 

Retail  Delivery  of  Milk. — The  delivery  of  milk  has  undergone  a  great 
change  within  a  few  years.  Prior  to  the  introduction  of  the  glass  bottle 
the  dealer  carried  his  milk  in  bulk  in  large  tin  cans  on  the  wagon  and 
appeared  at  the  door  with  the  can  over  his  arm  and  a  quart  measure  in 
his  hand  ready  to  deliver  the  amount  of  milk  the  customer  needed  for 
the  day.  At  a  little  later  period  in  place  of  the  dozen  or  two  cans  of  milk, 
there  were  placed  in  the  front  of  the  wagon,  two  huge  ones  with  stirrers 
and  faucets  out  of  which  the  milk  was  drawn  into  a  measure.  There 
were  three  principal  objections  to  the  delivery  of  milk  in  bulk,  namely: 
that  through  carelessness  or  design  one  customer  got  richer  milk  than 
another;  that  the  milk  was  seriously  contaminated  from  repeated  ex- 


340  CITY  MILK  SUPPLY 

posure  to  the  dust  of  the  street  and  the  dirty  hands  of  the  driver;  and 
that  the  mode  of  delivery  was  time-consuming  and  therefore  expensive. 

The  contamination  of  milk  in  the  course  of  delivery  was  studied  by 
Way  in  Cleveland,  Ohio,  in  November  and  December,  1906.  He  found 
that  in  the  average  of  40  samples  from  seven  different  dealers  the  "dip" 
milk  contained  an  average  of  37  per  cent,  more  bacteria  than  the  bottled 
milk;  that  the  "dip"  milk  contained  the  greater  number  of  bacteria  in 
77.5  per  cent,  of  the  samples;  that  16  samples  of  the  "dip"  milk  were 
over  50  per  cent,  and  eight  over  300  per  cent,  higher  than  the  correspond- 
ing bottled  sample;  that  the  bottled  milk  contained  the  greater  number 
of  bacteria  in  22.5  per  cent,  of  the  samples  and  of  these  but  three  were 
over  50  per  cent,  higher  than  the  "dip,"  the  highest  of  them  being  237.6 
per  cent. 

Dry  weather  with  a  stiff  breeze  during  delivery  usually  resulted  in  an 
increase  of  several  hundred  per  cent,  in  the  bacterial  content  of  the  "  dip  " 
milk  over  that  same  milk  served  in  bottles. 

In  small  communities  where  the  production  and  sale  of  milk  is  virtu- 
ally uncontrolled,  the  delivery  of  milk  by  the  dip  method  is  usual.  De- 
spite the  fact  that  delivery  of  milk  in  the  bottle  is  now  regarded  as  the 
best  way  to  handle  it,  the  method  was  slow  in  winning  public  approval. 
Customers  were  in  the  habit  of  getting  their  milk  from  cans  and  were 
loth  to  change.  Both  dealers  and  customers  looked  on  the  delivery  of 
milk  in  glass  as  likely  to  be  prohibitively  expensive  and  the  tidy  house- 
wife was  not  inclined  to  admit  to  her  home  glassware  that  circulated 
promiscuously  about  the  city.  Moreover,  the  milk  bottle  in  time  proved 
itself  to  be  an  occasional  vehicle  of  contagion.  However,  in  this  respect 
it  was  found  on  the  whole  to  be  no  more  dangerous  than  the  dip  method 
of  delivery  and  it  was  found  that  the  danger  from  infected  bottles  could 
be  very  successfully  controlled  by  a  provision  in  the  health  code  requiring 
the  daily  sterilization  of  milk  bottles.  Slowly  and  surely  the  bottles 
forced  out  the  dip  method  of  delivery.  They  have  the  advantages  that 
the  dealer  can  show  the  customers  the  cream  line  and  that  there  is  no 
sediment  in  the  milk;  they  make  an  attractive  package  and  are  convenient 
to  handle  both  on  the  route  and  in  the  homes. 

In  our  large  cities  the  delivery  of  dip  milk  has  almost  ceased  and  in 
many  of  them  is  forbidden  by  law.  However,  the  delivery  of  milk  in 
bulk  in  cans,  to  hospitals,  school  lunch  rooms,  various  public  institutions 
and  to  stores  is  often  permitted.  This  is  usually  a  concession  to  the  con- 
venience of  the  user  or  to  enable  him  to  get  milk  more  cheaply  and  should 
be  granted  only  with  the  understanding  that  conditions  attending  the 
delivery  and  storage  of  milk  will  receive  frequent  and  strict  inspection. 

In  places  where  the  milk  is  delivered  in  bottles  the  filling  of  bottles 
on  the  route  should  be  forbidden.  It  is  impossible  to  fill  them  on  the 
streets  in  a  cleanly  manner  and  without  exposing  the  milk  to  contamina- 


THE  MILK  CONTRACTOR  341 

tion  from  dust.  Sometimes  delivery  boys  will  fill  bottles  by  thrusting 
the  bottles  down  into  a  can  of  milk  thereby  contaminating  all  the  milk 
in  the  can  and  filling  the  bottles  with  dirty  milk. 

Progressive  dealers  give  a  great  deal  of  thought  to  the  delivery  of  milk 
for  if  it  is  not  watched  it  is  likely  to  become  unduly  expensive  while  close 
attention  to  the  service  is  apt  to  suggest  ways  in  which  expense  may  be 
cut  and  sales  increased. 

The  delivery  outfit  is  under  daily  observation  by  a  critical  public, 
consequently  it  is  worth  while  to  keep  it  spick  and  span.  The  horse 
should  be  well-groomed;  the  harness  should  be  clean  and  oiled  with  the 
trimmings  well-polished;  the  wagon  should  be  kept  well-painted  and 
washed.  The  driver  should  be  clean,  obliging  and  tactful.  A  uniform 
adds  to  his  appearance  if  it  is  kept  in  repair  and  clean.  The  advertising 
value  of  a  well-kept  delivery  outfit  is  well-known.  A  dirty  one  is  prima 
facie  evidence  of  an  insanitary  supply.  A  jaded  half -starved  horse  tells 
of  the  lack  of  prosperity  of  the  owner,  perhaps  of  his  willingness  to  take 
advantage  of  others.  An  attractive  wagon  every  moment  it  is  on  the 
road  extends  a  fetching  invitation  to  do  business  with  the  owner.  The 
color  of  the  wagon  may  well  be  distinctive  but  garish  colors  should  be 
avoided.  The  trade  mark  or  some  phrase  descriptive  of  the  dairy  or  of 
the  goods  may  well  be  printed  on  the  wagon  but  the  lettering  should  be 
plain  and  simple.  The  appearance  of  many  delivery  wagons  is  spoiled 
by  carrying  too  much  lettering  and  by  that  which  is  poorly  done.  A  clean 
good-mannered  deliveryman  will  get  trade  where  a  dirty,  smelly,  uncouth 
fellow  will  fail.  The  public  regards  the.  man  on  the  wagon  as  merely  a 
driver  but  his  employers  look  on  him  as  a  salesman.  It  is  his  ability  to 
get  trade  and  not  that  to  pilot  a  wagon  that  makes  him  valuable.  He  is 
often  paid  a  commission  for  new  business  or  given  a  bonus  as  a  reward 
for  his  contribution  to  the  general  prosperity  of  the  company.  Some  of 
the  larger  companies  give  their  deliverymen  lessons  in  salesmanship  and 
see  to  it  that  they  are  instructed  on  such  matters  as  the  chemical  com- 
position of  milk,  its  food  value,  the  bacterial  count,  pasteurization,  the 
methods  of  handling  milk  in  the  plant  and  on  the  way  it  should  be  cared 
for  in  the  home.  It  should  be  the  object  of  the  dealer  to  secure  certain 
and  regular  delivery  of  the  milk  and  to  cater  to  the  needs  and  wishes  of 
his  customers.  Particular  pains  should  be  taken  that  new  customers  are 
not  overlooked  or  special  orders  forgotten.  On  certain  holidays  such  as 
Christmas  or  Easter  it  may  be  customary  for  the  patrons  to  take  more 
cream  and  by  calling  attention  to  the  approach  of  the  day  the  company 
can  often  take  orders  which  it  would  have  to  refuse  were  they  not  booked 
ahead  of  time.  The  good  will  of  patrons  is  often  won  by  seeing  to  it 
that  the  milk  is  delivered  at  some  particular  spot  where  it  is  wanted  in- 
stead of  decorating  the  front  door  step  or  some  other  equally  prominent 
place  with  the  bottles.  Frequently  a  suggestion  that  a  covered  recep- 


342 


CITY  MILK  SUPPLY 


tacle  for  the  milk  will  protect  it  from  the  heat,  dogs,  cats  and  flies  and 
perhaps  from  being  stolen  is  a  good  stroke  for  both  the  company  and  the 
consumer.  Some  delivery  men  get  disliked  by  cutting  across  lawns  and 
flower  beds.  A  noisy  driver  is  an  infernal  nuisance.  In  the  modern 


L  S  U  P  P  L*2 


FIG.  47. — Delivery  wagon  in  which  the  driver  mounts  over  the  wheel. 

city,  so  many  keep  late  hours  and  there  are  so  many  night  workers  that 
a  driver  who  shouts  at  his  horse  and  rattles  the  bottles  about  becomes 
deservedly  unpopular.  Some  towns  like  Brookline,  Mass.,  have  made  a 


FIG.  48. — Delivery  wagon  with  the  door  between  the  wheels. 

special  effort  to  abate  the  noise  attendant  on  early  morning  deliveries 
and  among  other  things  have  had  rubber-tired  wagons  adopted. 

Milk  is  not  ordinarily  delivered  with  a  team;  when  one  is  used  the 
route  is  generally  a  long  one  or  the  milk  is  hauled  into  the  city  from  a  dairy 
farm  nearby.  Ordinarily  deliveries  are  made  in  a  one-horse  wagon. 


THE  MILK  CONTRACTOR 


343 


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344 


CITY  MILK  SUPPLY 


All  delivery  wagons  should  be  covered.  They  are  of  three  principal 
types.  That  most  used  is  one  where  the  driver  mounts  over  the  wheel 
and  is  open  at  the  ends;  in  some  cities  the  wagon  with  a  step  between  the 
wheels  and  a  door  in  the  middle  is  used.  In  still  others  the  step  and  door 
is  at  the  rear  and  the  man  drives  standing  up  with  the  cases  of  bottles  in 
front  of  him. 

The  cost  of  operating  milk  wagons  varies  greatly  in  different  cities 
according  to  the  price  paid  for  horses,  labor,  feed,  stabling,  etc.  Some 
data  furnished  by  Thomson  are  given  in  Table  100. 

The  life  of  a  horse  and  of  a  wagon  depends  on  their  quality  and  on  the 
usage  and  care  they  receive  and  of  course  varies  a  great  deal  with  these 


FIG.  49.- — Delivery  wagon  with  the  door  in  the  rear. 

different  factors.     So  far  as  the  writer  has  been  able  to  find  out  by  inquiry 
the  usual  estimate  of  the  life  of  each  is  3  or  4  years. 

The  delivery  routes  should  not  be  allowed  to  grow  up  in  haphazard 
fashion,;  on  the  contrary,  they  should  be  carefully  planned.  Generally 
the  more  deliveries  per  mile  traveled,  the  less  is  the  cost  of  delivery  per 
quart,  and  delivery  over  well-paved  streets  is  attended  with  the  least 
wear  and  tear  on  the  horse  and  wagon.  Therefore,  it  should  be  the  aim 
of  the  dealer  to  build  up  his  business  in  well-populated  and  well-cared-f or 
sections  of  the  city.  He  should  know  the  amount  of  milk  carried  and  the 
distance  traveled  by  each  wagon.  The  routes  of  the  several  wagons  should 
be  laid  out  in  such  a  way  that  they  cross  and  recross  each  other  as  little 
as  possible.  Conditions  in  the  residential  sections  should  be  studied; 
in  some,  the  houses  are  flush  with  the  sidewalk  while  in  others,  they  may 


THE  MILK  CONTRACTOR 


345 


set  back  a  long  way;  of  course  it  takes  more  time  and  therefore  costs  more 
to  deliver  to  the  latter.  In  apartment-house  districts  it  should  be  noted 
whether  deliveries  are  made  on  the  ground  floor  for  the  whole  house  or 
whether  deliveries  are  made  on  all  the  floors. 

The  Dairy  Division  of  the  U.  S.  Department  of  Agriculture  has  col- 
lected data  with  regard  to.  the  distribution  of  milk  that  are  set  forth  in 
Tables  101  and  102  and  a  Committee  of  the  International  Milk  Dealers' 
Association  received  reports  from  21  of  its  members  representing  three 
Provinces  and  13  States  as  to  the  number  of  hours  their  milk  remained 
on  the  delivery  wagons;  the  information  is  summarized  in  Table  103. 

TABLE  101. — AVERAGE  LOAD  CARRIED  BY  MILK  DELIVERY  WAGONS  IN  FIVE  CITIES  OP 
THE  UNITED  STATES  (U.  S.  DEPARTMENT  OP  AGRICULTURE) 


City 

Total  number  of  gal-     • 
Ions  included 

Total  number  of  wag- 
ons included 

Average  load  in 
gallons 

District  of  Columbia  .  . 

13,202 

173 

76.3 

Boston  

22,599 

305 

74.0 

Pittsburgh  

'9,190 

125 

73.5 

Baltimore  

12,614 

182 

69.3 

Philadelphia  

39,512 

571                             69.2 

TABLE  102. — MILES  TRAVELED,  LOAD  CARRIED  AND  QUARTS  DELIVERED  BY  THE 
WAGONS  OF  DEALERS  IN  FOUR  CITIES  OP  THE  UNITED  STATES  (U.  S.  DEPARTMENT 

OP  AGRICULTURE) 


City 

Number 
of 
wagons 

Number 
of 
dealers 

Ave.  miles 
traveled 

Number  of 
miles  vary- 
ing   from 

Average  load 
in  quarts 
per  wagon 

Number  of 
quarts  vary- 
ing from 

Pittsburgh  
District  of  Columbia...  . 

41 
63 

1 

14 

14.20 
18.60 

5.5-30.7 
10.4-30.0 

327.0 
301.8 

183-448 
140-648 

Baltimore  
Boston 

11 

22 

1 

1 

20.20 
20  35 

9.9-30.5 
7.7-43  6 

215.0 
245.0 

112-316 
180-290 

It  should  be  recognized  that  the  cost  of  delivering  milk  in  pint  bottles 
is  greater  than  for  delivering  in  quarts,  for  pint  bottles  take  longer  to 
fill  and  clean  and  disappear  from  service  faster  than  quarts.  It  takes 
as  long  for  a  driver  to  deliver  a  quart  of  milk  as  a  pint  and  of  course  the 
return  for  his  time  is  less.  So  the  dealer  is  justified  in  charging  a  higher 
rate  for  milk  delivered  in  pints  than  for  that  in  quarts. 

The  delivery  of  milk  in  quart  as  compared  with  pint  bottles  was 
studied  by  the  Dairy  Division  of  the  U.  S.  Department  of  Agriculture. 
The  results  thereof  appear  in  Table  104. 

Thus  41  per  cent,  of  the  bottled  'milk  of  74  dealers  was  put  out  in  pint 
bottles  and  they  each  handled  1.39  pint  bottles  to  every  quart  bottle. 

Pint  and  J^-qt.  bottles  are  used  in  certain  deliveries  such  as  those  at 


346 


CITY  MILK  SUPPLY 


hotels 


and  restaurants  where  milk  is  served  in  the  original  container  and 
are  profitable  partly  because  the  loss  of  bottles  is  small; 
therefore,  a  dairyman  is  justified  in  taking  on  this  class 
of  trade. 

Another  matter  to  be  considered  is  whether  one  or 
two  deliveries  shall  be  made  a  day.  The  reasons  ad- 
vanced for  two  deliveries  are  that  the  customer  re- 
ceives his  milk  fresher  and  so  in  hot  weather  in  better 
condition,  and  from  the  dealer's  point  of  view  that  his 
wagon  is  likely  to  pick  up  extra  orders  on  the  second 
trip,  and  his  drivers  have  more  time  for  canvassing 
and  bill  collecting.  The  advantage  that  may  come 
to  the  customers  from  receiving  fresher  milk  is  to  some 
extent  offset  by  the  fact  that  it  may  be  less  thoroughly 
cooled  before  being  loaded  onto  the  wagon  and  there  is 
a  disadvantage  to  the  dealer  in  that  the  second  de- 
livery is  made  in  a  much  warmer  period  of  the  day  so 
that  the  milk  requires  more  ice.  Studies  by  the 
Dairy  Division  of  four  routes  of  two  dealers  in  a  city 
where  two  deliveries  a  day  were  customary  showed 
that  the  second  trip  was  70  per  cent,  as  long  as  the 
first  and  required  97  per  cent,  as  much  time  but  that 
less  than  20  per  cent,  as  much  milk  was  delivered. 
The  amount  was  so  small  that  it  might  easily  have 
been  carried  on  the  first  load. 

The  first  careful  study  of  milk  distribution  made  in 
the  United  States  was  that  by  Williams  of  Rochester, 
N.  Y.  Some  of  the  conclusions  he  reached  were:  that 
such  distribution  of  milk  as  is. found  in  Rochester  and 
most  American  cities  is  very  wasteful  and  is  respon- 
sible for  much  of  the  bad  milk  sold;  that  were  this 
waste  avoided  by  proper  methods  of  distribution, 
cleaner  and  better  milk  could  be  furnished  the  con- 
sumer at  2  cts.  a  quart  less  than  he  now  pays;  that 
the  attempt  to  improve  the  quality  of  public  milk 
supplies  without  taking  cognizance  of  the  tremendous 
wastes  in  present  methods  of  distribution  undoubtedly 
accounts  for  the  failure  to  advance  in  the  solution  of 
the  municipal  milk  problem. 

Table  105  shows  how  in  every  one  of  the  sections 
studied  an  unnecessary  number  of  distributors  were 
pounding  the  roads  to  pieces  with  their  wagons  and 
how  the  territory  might  be  covered  by  a  single 
distribution. 


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THE  MILK  CONTRACTOR 


347 


TABLE  104. — THE  DELIVKRY  OF  MILK  IN  PINT  AS  COMPARED  WITH  QUART  BOTTLES 
IN  FIVE  CITIES  OF  THE  UNITED  STATES  (U.  S.  DEPARTMENT  OF  AGRICULTURE) 


City 

1 

Number  of 
dealers 

Number  of 
quarts 

Number  of 
pints 

Proportion     of 
pints  to  quarts 

Boston                     .  . 

27 

99,844 

64,830 

0.65 

Washington 

13 

33,356 

35,600 

1  06 

Pittsburgh  

9 

26,917 

37,040 

1.37 

Philadelphia 

15 

80,922 

173,300 

2.14 

Baltimore  

10 

18,713 

50,738 

2.71 

Total.. 

74 

259,752 

361,508 

1.39 

TABLE  105. — UNNECESSARY  STREET  TRAFFIC  OF  MILK  DISTRIBUTORS  IN  ROCHESTER, 

N.  Y.   (WILLIAMS) 


Class 

•.  ! 

No.    of 
homes  in 
section 

No.  of  homes 
supplied   by 
distributors 

No.   of  distrib- 
utors supply- 
ing section 

No.  of  miles 
distributors 
now  travel  in 
supplying 
section 

No.    of   miles   a 
single   distributor 
would  travel  in 
section  to  render 
same  service 

Chiefly  colored  .... 

231 

165 

23 

20 

2.0 

American  laboring. 

523 

432 

55 

45 

3.0 

American  laboring  . 

462 

340 

40 

30 

3.0 

American  laboring  . 

191 

167 

31 

21 

1.7 

American  laboring  . 

786 

786 

62 

57 

5.4 

German-American 

laboring  

527 

508 

39 

61 

4.4 

German  laboring  .  .  . 

234 

145 

39 

20 

1.7 

Italian  laboring.  .  .  . 

643 

253 

61 

36 

2.0 

Jewish  laboring.  .  .  . 

477 

363 

57 

30 

1.7 

American  middle  .  . 

450 

443 

26 

48 

2.4 

Well-to-do          "ivii 

283 

273 

27 

24 

2.6 

Well-to-do  

120 

120 

14" 

12 

1.2 

Well-to-do  

201 

166 

25 

21 

2.5 

Well-to-do  

99 

91 

17 

14 

2.0 

Well-to-do  

209 

216 

34 

38 

2.5 

Williams  divides  the  distributors  in  Rochester  into  four  groups  accord- 
ing to  the  volume  of  business  done.  The  first  group  is  composed  of  25 
dealers  who  sell  not  more  than  150  qt.  of  milk  daily;  the  second  group 
consists  of  101  distributors  who  sell  from  151  to  300  qt.;  the  third  is  made 
up  of  44  dealers  who  distribute  from  131  to  1,000  qt.;  in  the  fourth  group 
are  three  companies  who  dispense  from  3,000  to  8,000  qt.  In  Table  106 
is  shown  the  result  of  Williams'  study  of  the  business  of  these  dealers. 

As  illustrative  of  Williams'  analysis  of  Table  106  his  remarks  in  re- 
gard to  the  25  distributors  selling  not  more  than  25  qt.  a  day  may  be 
quoted.  These  distributors  require  the  services  of  29  men,  34  horses 
and  26  wagons.  They  travel  199  miles  to  supply  3,016  qt.  of  milk  to 


348 


CITY  MILK  SUPPLY 


TABLE  106. — THE  TOTAL  ACCOUNTING  OF  MILK  DISTRIBUTORS  OF  ROCHESTER,  N.  Y., 
GROUPED  ACCORDING  TO  THE  VOLUME  OF  BUSINESS  DONE  (WILLIAMS) 


Schedules 

Distributors  selling  daily 

Total 

Not  more 
than  150 
qt. 

From  151 
to  300 
qt. 

From  301 
to  1,000 
qt. 

1,000 
qt.  or 
more 

Distributors,  number  

Milk,  retail,  quarts  
Milk,  wholesale,  quarts  .  .  . 

Total  milk  sold,  quarts.. 

Men  employed,  number.  .  .  . 
Horses  employed,  number.  . 
Wagons  employed  
Length  of  route,  miles  
Customers,  number  

Value  milk-room  equipment 
Value  horses  and  wagons.  .  . 
Value  real  estate  

Total  investment  

25 

101 

44 

3 

173 

2,887 
129 

21,368 
2,411 

17,180 
3,415 

8,900 
6,000 

50,335 
11,947 

3,016 

23,799 

20,599 

14,900 

62,314 

29 
34 
26 
199 

1,885 

133 
160 
137 
1,053 
13,915 

99 
101 
92 
616 
9,490 

95 
65 
50 
641  . 

9,800 

356 
360 
305 
2,509 
35,090 

$2,407 

8,815 

$17,295 
45,105 

$16,750 
28,495 

$38,450 
25,035 
96,700 

$76,902 
107,450 
96,700 

111,222        $62,400 

$44,245 

$160,185 

$278,052 

Interest,    depreciation    on 
investment  

$6.17 
8.92 
4.35 

25.30 
5.60 

7.38 

$34.17 
42.25 
36.59 

152.50 
48.95 
77.36 

$25.16 
39.03 

28.55 

101.00 
74.20 
74.89 

45.15 
17.20 

14.55 

100.00 
193.06 
21.00 

$110.65 
107.40 
84.04 

378.80 
321.81 
180.63 

Cost  of  coal  and  ice  
Milk  shrinkage,  waste,  etc. 
Maintenance     horse     and 
wagon  
Daily  wages,  labor 

Cost  of  bottles  

Total  cost  distribution.  .  . 
Amount  paid  producer  

Total  cost  to  distributor  . 

Milk  receipts,  retail  
Milk  receipts,  wholesale.  .  .  . 
Cream  receipts 

$57.72 
128.71 

$392.82 
999.55 

$342.83 
880.44 

$390.98 
886.40 

$1,184.35 
2,895.10 

$186.43    $1,392.37 

$1,223.27 

$1,277.38 

$4,079.45 

$213.31 
1.00 
6.75 

$1,535.05 
138.26 
60.84 

$1,254.67 
195.87 
106.20 

$682.00 
314.50 
67.51 

$3,685.03 
548.63 
241  .  50 

Total  receipts  .  .  . 

$220.06 
37.59 
3.96 

$1,734.15J  $1,556.74 
341.78         333.47 

$1,366.01 

78.58 

$4,876.96 
791.42 

Labor  profit.  . 

Labor  loss  

2,270  homes.  There  is  invested  in  23  insanitary,  poorly  equipped  milk 
rooms,  $3,300;  in  inferior  horses  and  wagons  $8,815.  The  wage  and  labor 
profit  received  by  these  29  men  is  approximately  $33.63  daily,  an  aver- 


THE  MILK  CONTRACTOR  349 

age  of  $1 . 16  per  day  per  man.  If  this  service  were  concentrated  in  one  sec- 
tion under  a  single  efficient  distributing  agency,  thus  avoiding  overlapping 
routes,  waste  of  labor  and  reduplication  of  equipment,  it  could  be  ren- 
dered in  a  superior  manner  by  a  much  smaller  force  and  equipment  as 
indicated  in  Table  107. 

TABLE  107. — COST  OF  DISTRIBUTING  3,016  QT.  OP  MILK  BY  25  PETTY  DISTRIBUTORS 
OP  ROCHESTER,  N.  Y.,  COMPARED  WITH  COST  OF  DISTRIBUTING  THE  SAME 

UNDER  A  MODEL  SYSTEM  (WILLIAMS) 
Under  present  system  "Under  model  system 

29  men  at  $1.16  per  day $33.63     3  men  at  $2.50  per  day $7.50 

34  horses  and  26  wagons,  main-  4  horses,  daily  maintenance 5 . 00 

tenance 26. 00     1  truck,  maintenance 0.25 

1  motor  truck  part  of  1  day 2 . 00 

Total $59.63     Superintendence 6.00 


$20.75 

The  $3,300  now  invested  in  23  small  insanitary  milk  rooms  would 
furnish  a  very  good  equipment  for  one  sanitary  milk  depot.  A  complete 
outfit  of  horses  and  trucks  could  be  had  for  $1,100,  a  saving  of  at  least 
$7,700.  The  economies  that  could  be  effected  by  these  and  other  unnec- 
essary wastes  on  this  amount  of  service  would  lessen  the  cost  of  distribu- 
tion by  about  $40  per  day,  or  1.5  cts.  per  quart. 

Table  108  is  Williams'  statement  of  the  delivery  of  milk  in  Rochester 
at  the  present  time  and  how  it  might  be  delivered  under  a  model  system. 

TABLE  108. — THE  DELIVERY  OF  MILK  IN  ROCHESTER,  N.  Y.,  AS  AT  PRESENT,  AND  AS 
IT  MJGHT  BE  DELIVERED  UNDER  A  MODEL  SYSTEM  (WILLIAMS) 
Present  system  Model  system 

356  men  and  in  many  cases  their  families    90  men 
380  horses  50  horses 

305  wagons  25  horse-drawn  trucks 

2,509  miles  of  travel  300  miles  of  travel 

$76,600  invested  in  milk-room  equipment    $75,000  equipment  for  sanitary  plants 
$108,000  invested  in  horses  and  wagons          $30,750  equipment  of  horses  and  trucks 
$2,000  present  daily  cost  of  distribution       $600  estimated  daily  cost  of  distribution 
$720,000  present  yearly  cost  of  distribu-    $22,000  estimated  yearly  cost  of  distribu- 
tion tion. 

The  same  conditions  exist  in  other  American  cities;  thus  the  Dairy 
Division  of  the  U.  S.  Department  of  Agriculture  in  1915  found  that  in  the 
District  of  Columbia  the  shortest  distance  traveled  by  any  one  of  98 
wagons  studied  was  10.4  miles  and  the  longest  was  30,  the  average  being 
19.1  miles.  At  the  time  there  were  510  miles  of  street  and  250  wagons  in 
the  district  so  that  if  each  wagon  covered  19.1  miles  they  traveled  in  all 
4,775  miles  or  93  times  the  total  number  of  miles  of  street  and  about  eight 
out  of  every  nine  wagons  were  used  uneconomically.  More  than  SO^deal- 
ers  were  making  deliveries. 


350  CITY  MILK  SUPPLY 

While  the  single  central-delivery  system  looks  very  attractive,  its 
practicability  is  not  unchallenged.  The  objections  raised  to  it  by  milk 
dealers  of  New  England  are  set  forth  in  the  Boston  Chamber  of  Commerce 
report  of  1915.  They  are  that  there  would  be:  (1)  Loss  in  teams  and 
trucks,  for  each  company  would  have  to  maintain  motor  trucks  or  teams 
to  carry  its  product  to  the  central  delivery  plant  which  vehicles  would 
be  idle  the  greater  part  of  the  day.  (2)  There  would  be  difficulty  in 
stacking  the  load,  for  it  would  be  impossible  to  load  the  delivery  truck 
in  such  a  way  that  the  several  brands  of  milk  and  the  various-sized  bottles 
of  the  different  dealers  could  be  handled  with  celerity.  (3)  Only  by 
giving  advance  orders  could  the  customer  obtain  extra  milk  since  it 
would  be  impossible  for  the  wagon  to  carry  a  surplus  supply  of  all  dealers. 
(4)  The  loss  in  bottles  would  be  greatly  increased  as  no  one  would  take 
as  keen  an  interest  in  the  recovery  of  bottles  as  the  present  drivers  or 
salesmen  do.  (5)  The  drivers  solicit  trade,  collect  bills  and  look  after 
bottles,  but  under  a  central-station  system  each  dealer  would  have  to  hire 
one  or  more  men  to  attend  to  these  things.  (6)  The  cost  of  advertising 
would  be  increased  because  the  advertising  that  each  dealer  now  gets 
from  his  own  delivery  wagon  would  be  eliminated. 

There  are  three  ways  in  which  a  central-delivery  system  might  be 
operated,  namely:  (1)  by  the  producers  on  a  cooperative  system;  (2)  by 
dealers  as  a  joint  stock  company;  and  (3)  as  a  municipally  owned  plant. 
There  have  been  but  few  central-delivery  systems  operated  in  the  United 
States  so  that  conclusions  cannot  be  drawn  from  practice  but  such  at- 
tempts as  have  been  made  at  operating  them  have  not  been  long-lived. 
Producers  as  a  rule  lack  in  experience  and  have  strong  individualistic 
tendencies  so  that  they  are  liable  to  losses  from  mismanagement  and  the 
tendency  of  members  of  the  cooperative  association  to  break  away  and 
strike  out  for  themselves.  At  Topeka,  Kan.,  for  example,  the  Producers 
Creamery  Co.  went  to  the  wall  after  a  brief  existence.  In  some  small 
cities  as  DeKalb,  111.,  Kalamazoo,  Mich.,  and  Lawrence,  Kan.,  private 
companies  for  a  time  have  been  practically  the  sole  distributors  and  have 
been  able  to  render  efficient  service  at  low  cost  but  such  companies  as  a 
rule  lack  stability  for  some  stockholder  or  outsider  sees  a  chance  for  a 
bigger  profit  and  starts  competition.  The  nearest  approach  to  privately 
operated  single  plants  are  those  of  the  big  metropolitan  dealers  of  which 
there  are  usually  but  two  or  three,  certainly  but  few,  and  rarely  only  one 
in  a  city.  These  large  companies  reduce  but  do  not  entirely  eliminate 
the  loss  that  arises  from  numerous  delivery  wagons  traversing  the  same 
streets  every  morning. 

A  municipally  owned  milk  plant  looks  particularly  attractive  to  the 
small  city  where  no  one  dealer  has  felt  justified  in'expending  the  capital 
to  erect  and  equip  a  modern  plant  for  clarifying,  pasteurizing,  cooling 
and  bottling  milk.  It  is  felt  that  the  city  might  do  this  and  that  an  ex- 


THE  MILK  CONTRACTOR  351 

pert  might  be  hired  to  run  the  plant  and  to  teach  the  dairy  farmers  better 
methods  of  production.  Large  cities,  too,  have  considered  the  proposi- 
tion. In  1915  the  matter  was  brought  to  a  head  in  Seattle,  Wash.,  where 
a  dealer  applied  for  the  sole  privilege  of  distributing  milk  in  the  city. 
The  council  determined  to  investigate  the  advantages  of  a  municipally 
owned  plant.  The  city's  milk  inspector,  A.  N.  Henderson,  has  already 
filed  a  preliminary  report  on  the  matter  and  is  continuing  his  investiga- 
tion. In  the  course  of  his  studies  he  was  unable  to  find  a  single  munici- 
pally operated  plant  in  the  United  States.  Undoubtedly  the  reason  that 
the  experiment  has  not  been  tried  is  that  the  people  positively  decline 
to  entrust  the  care  of  such  a  vital  necessity  as  milk  to  American  commer- 
cial politics. 

The  milk-consuming  public  would  very  much  like  to  know  what  the 
profits  in  the  city  milk  business  are.  Some  people  believe  them  to  be 
large,  others  are  of  the  opinion  that  they  are  moderate  while  dealers  as 
a  whole  volunteer  very  little  information  on  the  subject.  Some  contrac- 
tors state  that  taking  the  country  as  a  whole,  the  profit  ranges  on  the 
average  from  J£  to  J^  ct'.  per  quart  of  bottled  milk.  The  only  specific 
statement  of  a  larger  dealer  that  the  writer  has  seen  in  print  is  that  of 
H.  P.  Hood  and  Sons  of  Boston,  Mass.,  which  is  presented  in  Table  109. 

TABLE  109. — COST  OP  DELIVERING  1  QT.  OP  MILK  TO  THE  CONSUMERS  (H.  P.  HOOD 

AND  SONS) 

Per  quart 

Country  expenses : 

Transportation,  labor,  ice,  cans  and  stoppers,  can  washers  and  miscel- 
laneous items $0.0102 

City  expenses: 

Pasteurizing,  washing  and  bottling,  glass  jars,  etc 0. 0103 

Salaries  of  drivers,  helpers,  foremen  and  salesmen 0.0127 

Teams  expense,  including  horses,  wagons  and  harness 0 . 0070 

Miscellaneous  expenses,  including  bookkeeping,  stationery,  advertising 

matter,  carfares,  telephone  calls  and  bad  debts 0 . 0038 


Total  city  expenses $0.0338 

Total  expenses,  city  and  country 0 . 0440 

Shrinkage  at  2  per  cent,  and  loss  in  carrying  surplus 0 . 0037 


Grand  total  expenses ....  $0 . 0477 

Average  price  paid  producer  per  quart  in  the  middle  zone  from  Oct.  1, 

1911,  to  Oct.  1,  1912 0.0390 


Net  cost  per  quart  delivered  to  customer,  family  trade ! $0 . 0867 

As  the  average  price  paid  per  quart  for  bottled  milk  in  Boston  is 
9  cts.,  the  profit  according  to  these  figures  is  J^  ct.  a  quart. 

At  the  time  of  the  milk  strike  in  New  York  in  the  autumn  of  1916, 
Borden's  Condensed  Milk  Company  issued  the  statement  on  the  cost  of 
milk  that  appears  in  Table  110. 


352  CITY  MILK  SUPPLY 

TABLE  110. — STATEMENT  OF  THE  AVERAGE  PRICE  RECEIVED,  CLASSIFIED  COST  AND 
NET  PROFIT  REALIZED  PER  QUART  OF  MILK  HANDLED  BY  BORDEN'S 
CONDENSED  MILK  COMPANY  IN  EASTERN  TERRITORY  DURING  THE 
YEAR  ENDED  JUNE  30,  1916 

Price  Received :  . .  $0 . 0803 

Cost: 

Milk 0.0369 

Factory  expense 0 . 0126 

Freight .  . 0. 0072 

Selling  and  delivery  expense 0. 0201 

General  expense 0 . 0009 


Total  cost $0.0777 


Net  profit 0.0026 

Percentage  of  profit  on  net  sales 3 . 25  per  cent. 

Stated  in  another  form  the  Company  says  that  of  the  consumer's 
dollar  16.44  ct.  goes  for  materials  and  supplies  such  as  bottles,  cans,  feed, 
bedding,  ice,  etc.,  for  the  railroad  9.03  ct.,  for  labor  25.41  ct.,  for  the 
dairyman  45.87  ct.  and  to  the  stockholders  of  the  company  3.25  ct. 

The  cost  of  producing  and  of  delivering  milk  to  the  consumer  must 
vary  considerably  in  the  different  dairy  sections  and  cities  but  such  in- 
formation as  the  writer  has  leads  him  to  the  opinion  that  there  is  not  a 
great  difference  in  the  profit  per  quart  of  bottled  milk  which  is  made  by 
the  dealers  of  the  eastern  half  of  the  United  States. 

With  regard  to  the  cost  of  operating  a  small  milk  route  Kelly  has 
recently  made  the  following  estimate.  The  equipment  required  and  the 
cost  thereof  for  handling  75  gal.  a  day  in  250-qt.  packages  is  shown  in 
Table  111. 

TABLE  111. — INVESTMENT  REQUIRED  TO  OPERATE  A  MILK  PLANT  HANDLING  75  GAL.  A 

DAY  (KELLY) 

Boiler $150  Motor ...     $75 

Bottle  filler 150  Miscellaneous 150 

Pasteurizing  outfit 275  Cans 40 

Bottle  washer. .  75  Bottle  cases ..  30 


Total $945 

Charging  25  per  cent,  as  the  annual  rate  of  interest  and  depreciation 
on  the  $945  invested  in  plant  equipment  and  15  per  cent,  on  the  $500 
that  would  have  to  be  invested  in  delivery  equipment  and  dividing  these 
charges  by  12  the  statement  arrived  at  in  Table  112  gives  a  fair  idea  of 
the  probable  monthly  expenses. 

If  the  milk  was  purchased  at  4  cts.  a  quart  $360  would  have  to  be 
added  to  this  monthly  expense  which  would  make  a  total  of  $529.68.  If 
9,000  qt.  were  sold  at  7  cts.  a  quart  it  would  yield  a  gross  income  of  $630 
per  month  which  would  leave  approximately  $100.32  for  the  labor  and 


THE  MILK  CONTRACTOR 


353 


TABLE  112. — MONTHLY  EXPENSES  OP  OPERATING  A  75-QAL.  DELIVERY  ROUTE  (KELLY) 

Interest  and  depreciation  on  $945 

Interest  and  depreciation  on  $500,  delivery  equipment 


Rent  of  building $30.00 

Keeping  of  horses 20 . 00 

Helper 40.00 

Coal 6.00 

Ice 12.00 

Electricity 1.50 


Caps 

Water 

Bottles 

Washing  powder 

Miscellaneous  expenses 
Shrinkage  and  cans .  .  . 


Total $169.68 

TABLE  112. — VARIATION  OP  COST  OP  EACH  OPERATION  PER  QUART 
(Boston  Chamber  of  Commerce,  1915) 


Operation 

Cost 

Varying  figures  of  different  companies 

Collection 

"Lowest  .  .  . 
Highest 
Usual  (c) 
Lowest 
Highest 
Usual 

Lowest 
Highest 
Usual 

Lowest 
Highest 
Usual 

Lowest 
Highest 
Usual 

Lowest 
Highest 
Usual 

Lowest 
Highest 
Usual  .... 

$0.00250 
0.01500 
0.00625 

$0.00010 
0.01910 
0.00660 
0.00250 
0.01125 
0.00400 

0.00440 
0.01030 

0.00400 
0.00850 
0.00700 

0.02250 
0.05000 
0.03000 

0.01000 
0.35000 
0.015-0.02 

0.00400 
0.00529 
0.00470 

$0.00200 
0.01100 
0.00300 
0.00340 
0.00480 
0.00400 

0.00390 
0.00910 
0.00438 

$0.0068 
0.0235 
0.0095 

Country  plant  

0.00750(a) 

Railroad  transportation  .  . 
City  plant  

0.00500 

Distribution,  family  trade 
Distribution,  retail  stores 

Distribution,      wholesale 
trade 

0.0050(6) 

0.01350 

0.03860 

0.01880 
0.02190 
0.02050 

0.01030 
0.01280 
0.01130 

0.01000 

0.00500 

(a)  Including  pasteurization. 

(6)  Excluding  pasteurization. 

(c)  Since  there  is  a  great  difference  between  the  highest  and  lowest  costs  the 
"usual"  cost  is  often  far  from  the  cost  of  the  greater  part  of  the  milk  entering  metro- 
politan Boston. 

income  of  the  owner.  Losses  would  occur  from  bad  bills,  etc.;  100  gal. 
a  month  could  be  handled  with  practically  the  same  equipment  and  fig- 
ured on  the  same  basis  would  yield  a  theoretical  profit  of  $178  per  month. 

23 


354  CITY  MILK  SUPPLY 

The  Boston  Chamber  of  Commerce  report  of  1915  takes  up  the  cost 
of  distributing  milk  and  cream  in  New  England.  The  report  states  that 
milk  is  delivered:  (1)  to  family  trade  in  bottles;  (2)  to  retail  stores,  gen- 
erally in  cases  of  12  quart  bottles  or  20  pint  bottles;  (3)  to  wholesale 
customers  in  cans.  This  class  includes  hotels,  restaurants,  boarding 
houses,  institutions,  delicatessen  shops,  drug  stores,  bakeries,  ice  cream 
manufacturers,  etc.  In  Greater  Boston  the  milk  and  cream  is  appor- 
tioned to  these  three  classes  of  consumers  as  follows:  to  family  trade  in 
bottles,  milk  20  to  25  per  cent.,  cream  5  to  15  per  cent.;  to  retail  stores  in 
bottles,  milk  20  to  25  per  cent.,  cream  10  to  20  per  cent.;  to  wholesale 
consumers  in  cans,  milk  50  to  60  per  cent.,  cream  50  to  75  per  cent.  It 
is  estimated  that  since  there  are  fewer  hotels,  restaurants,  boarding  houses, 
etc.,  in  cities  of  100,000  inhabitants,  a  larger  percentage  of  the  milk  goes 
into  family  trade  and  that  in  cities  of  5,000  to  25,000  the  family  trade  is 
80  per  cent,  of  the  total. 

The  cost  of  each  operation  in  the  progress  of  the  milk  from  the  pro- 
ducer to  the  consumer,  the  report  sets  forth  as  in  Table  112. 

The  report  discusses  the  cost  of  the  several  items  as  follows: 

Collection. — The  cost  of  collection  from  the  producer  and  delivery  to  the 
country  plant  or  car  varies  from  Y±  to  1>£  cts.  per  quart,  depending  on  the  length 
of  the  route,  the  character  of  the  roads,  whether  hilly  or  level,  the  regularity  of 
amounts  collected  per  day  throughout  th§  entire  year,  and  the  total  amount  per 
day  the  entire  route  will  average.  Local  conditions  govern  this  entirely. 

Country  Plant. — Expenses  vary  here  from  Y±  to  1%  cts.,  depending  almost 
entirely  on  the  number  of  quarts  put  through  the  plant,  and  the  number  of  oper- 
ations necessary  before  loading  on  the  car,  and  the  great  variation  in  the  monthly 
receipts  of  milk  and  cream  (since  the  overhead  expenses  remain  practically  the 
same  throughout  the  12  months,  and  in  many  sections  there  is  an  extreme  varia- 
tion in  the  monthly  receipts;  receive  more  in  April,  May,  June  and  July  than  in 
the  other  8  months). 

Transportation  on  Railroads. — This  varies  from  Y±  to  \y±  cts.  in*  leased  cars, 
according  to  the  distance,  the  number  of  railroads  the  car  uses,  the  number  of 
days  the  cars  fail  to  carry  the  minimum  number  of  quarts  which  must  be  paid  for 
per  carload,  the  number  of  days  the  milk  and  cream  has  to  be  iced,  and  the 
number  of  stops  necessary  to  complete  a  carload  (this  requiring  the  services  of 
one  or  more  caretakers). 

Rates  on  milk  and  cream  shipped  by  express  and  as  "excess  baggage"  are 
not  given  in  the  table  or  compared,  as  this  will  be  found  under  the  head  of  "  Rail- 
road Transportation." 

City  Plant. — The  cost  varies  from  ^  to  1}^  cts.,  depending  on  the  overhead 
charges  of  the  plant,  the  arrangement  and  machinery  in  operation,  the  regular 
amount  of  the  milk  put  through  and  the  cost  of  labor  and  ice. 

DISTRIBUTION 

Family  Trade. — The  cost  here  varies  from  2>£  to  5  cts.  in  bottles,  depending 
on  the  loss  in  bad  bills  (average  monthly  bill  of  30  qt.,  $2.70;  many  move  or 


THE  MILK  CONTRACTOR  355 

avoid  payment,  bill  too  small  to  pay  for  costs  of  collection,  but  the  aggregate  is 
a  substantial  amount),  non-return  of  bottles,  the  density  of  the  population,  the 
number  of  stops  required  to  deliver  a  load  (depending  on  whether  the  customer 
takes  a  pint,  quart  or  2  or  3  qt.),  and  the  average  number  of  quarts  that  are  carried 
through  the  year  (which  varies  from  200  to  400  qt.  per  team).  On  many  routes 
people  are  away  during  the  summer,  leaving  a  team  for  months  with  only  half 
of  its  regular  load. 

Retail  Stores  (Bottles  in  Cases). — The  cost  of  delivery  to  the  retail  stores 
varies  from  1  to  2>£  cts.,  depending  on  the  distance  traveled,  the  number  of  stops 
necessary  to  deliver  a  load  (10  to  35),  and  whether  or  not  two  trips  can  be  made 
in  a  day. 

Wholesale  Trade. — The  cost  to  the  wholesale  consumer  varies  from  >£  to  1  ct., 
depending  on  the  number  of  stops,  the  distance,  the  number  of  trips  a  two-horse 
team  or  motor  truck  can  make  in  a  day,,  and  the  size  of  the  container,  whether 
8-,  8^-,  20-  or  40-qt.  or  21^-qt.  container  (a  20-,  21^-  or  40-qt.  container  costing 
K  ct.  to  3^  ct.  per  quart  less  to  handle). 

Early  in  1915  the  Federal  Government  in  a  cooperative  investigation 
with  the  Massachusetts  Agricultural  College  obtained  the  cost  of  dis- 
tributing milk  from  86  dealers  in  six  cities  and  towns  of  Massachusetts, 
including  Worcester  and  Springfield.  The  cost  of  retailing  began  with 
the  delivery  of  the  milk  at  the  milk  plant  of  the  distributor,  or  in  the  case 
of  producers  with  the  preparation  of  the  milk  after  it  had  been  strained 
and  put  in  cans.  All  labor  costs  including  the  distributor's  own  valua- 
tion of  his  time  and  of  the  time  given  him  by  various  members  of  his 
family,  the  interest  on  the  investment,  depreciation,  insurance,  taxes, 
all  overhead  charges,  cost  of  horse  labor,  including  feed,  depreciation  on 
horses  and  equipment  and  all  losses  in  bottles  and  wastes  were  taken  into 
consideration.  The  cost  of  distributing  milk  figured  on  this  basis  means 
that  milk  could  be  delivered  at  this  cost  but  that  there  would  be  no  profit 
above  wages.  The  average  costeof  delivery  in  the  six  cities  was  2.64  cts. 
and  the  average  cost  for  the  42  dealers  in  Worcester  and  Springfield 
was  2.79  cts.  Increase  in  the  cost  of  labor  and  other  costs  since  the  study 
was  completed  makes  it  necessary  to  add  25  per  cent,  or  more  to  these 
figures. 

Cance,  who  conducted  the  investigation,  found  that  in  Springfield  one 
dealer  distributed  for  2.2  cts.  and  another  for  4.71  cts.  per  quart.  As 
a  whole  the  distributing  costs  run  about  as  follows: 

Of  the  dealers  investigated: 

6  per  cent,  distributed  milk  for  less  than  1%  cts. 
21  per  cent,  distributed  milk  for  l>£-2   cts. 
24  per  cent,  distributed  milk  for  2-2^  cts. 
19  per  cent,  distributed  milk  for  2^-3  cts. 
18  per  cent,  distributed  milk  for  3-33^  cts. 
12  per  cent,  distributed  milk  for  more  than  3)^  cts» 


356 


CITY  MILK  SUPPLY 


That  is  to  say,  70  per  cent,  of  the  dealers  handled  milk  for  less  than  3  cts. 
per  quart. 

These  tremendous  variations  are  due  to  a  variety  of  causes. 

1.  It  is  only  evident  that  the  methods  of  distributing  milk  are  not 
standardized.     There  is  no  agreement  as  to  the  size  of  plant  and  equip- 
ment necessary  to  handle  500  to  1,000  or  1,500  qt.  of  milk  per  day. 
Some  dealers  have  a  very  efficient  plant  with  small  operating  costs  and 
sell  good  milk  at  a  good  profit.     Others  by  their  own  inefficiency,  ill- 
proportioned  equipment  and  out-of-date  methods  are  making  little  or 
nothing  at  the  expense  of  the  consumer. 

The  fact  that  51  per  cent,  of  the  distributors  could  do  business,  and 
pay  themselves  wages,  interest  on  the  plant,  depreciation  and  all  losses  and 
expenses  for  less  than  2J^  cts.  per  quart  is  evidence  that  milk  can  be 
retailed  economically. 

2.  Delivery  costs  are  in  many  cases  very  high.     An  analysis  of  costs 
into  "  Preparation  for  Delivery,"  "  Deli  very"  and  "  Overhead  Expenses" 
by  groups,  is  as  follows: 


Preparation 
costs, 
cents 

Delivery 
costs, 
cents 

Overhead 
costs, 
cents 

Group  I  20  firms                              .        ... 

0.46 

0.89 

0.29 

Group  II,  10  firms       

0.45 

1.05 

0.32 

Group  III  27  firms                           .    .        .    . 

0.65 

1.14 

0.25 

Group  IV  20  firms 

0  90 

1.6 

0.43 

In  all  cases  delivery  is  a  large  item,  more  than  50  per  cent,  of  the  total. 
In  group  II  it  amounts  to  nearly  58  per  cent. 

3.  Long  hauls  and  small  loads  per  wagon  are  two  causes  for  high 
delivery  costs.  In  some  instances  the  long  hauls  are  necessary  but  often 
duplication  of  routes  and  long  distances  between  customers  are  responsi- 
ble for  miles  of  useless  travel  and  waste  of  both  men  and  horse  labor. 

The  small  load  is  sometimes  the  result  of  the  long  haul  since  the  long 
haul  decreases  the  number  of  deliveries  a  driver  can  make  in  a  given  time. 
It  is  obvious  that  one  man  can  deliver  more  milk  if  he  delivers  1  qt. 
at  every  house  than  if  he  delivers  a  quart  at  every  fifth  or  every  tenth 
house. 

On  the  other  hand,  loads  are  often  smaller  than  necessary,  even  under 
the  circumstances,  sometimes  because  of  poor  horse  and  wagon  equip- 
ment, sometimes  because  of  the  inefficiency  of  the  driver,  sometimes  for 
no  apparent  reason. 

4.  Many  losses   occur  because  of  the   competition  of  many  small 
dealers.     Surplus  milk- is  a  very  grave  problem,  especially  for  a  small 


THE  MILK  CONTRACTOR  .     357 

milkman.  A  large  dealer  can  utilize  his  surplus  at  a  comparatively 
small  loss. 

Losses  due  to  spoiled  milk  and  bad  debts  are  heavy  items  in  many 
cases  and  to  the  small  dealer  collections  are  unduly  expensive.  In  Spring- 
field the  loss  due  to  surplus,  spoiled  milk,  and  bad  accounts  as  reported 
by  ten  dealers  amounted  to  $3,379  annually  or  96  cts.  per  thousand 
quarts  delivered. 

Under  a  competitive  system  there  is  a  tendency  to  take  on  undesirable 
customers,  to  make  expensive  deliveries  and  to  carry  customers  who  buy 
milk  in  small  quantities  from  three  or  four  different  milkmen. 

Looked  at  from  almost  any  angle,  a  large  well-equipped  plant,  with 
outlying  stations  from  which  deliveries  can  be  made  over  well-planned 
routes  is  more  efficient  and  profitable  to  distributors  than  the  present 
unorganized  system  of  small  independent  competitive  units.  In  the  city 
of  Erie,  Pennsylvania,  the  producers  formed  a  milk  supply  company  about 
seventeen  years  ago  and  have  been  retailing  their  own  milk  to  the  greater 
part  of  the  population  ever  since.  The  venture  is  a  pronounced  success 
and  the  business  of  the  company  has  grown  rapidly  and  steadily. 

(a)  They  have  given  Erie  an  excellent  quality  of  milk. 

(6)  At  a  lower  price  to  the  consumer  than  any  neighboring  cities  of 
the  same  size. 

(c)  They  have  increased  the  load  per  driver,  shortened  the  routes 
amazingly  and  lessened  delivery  costs. 

(d)  By  means  of  a  bonus  system  they  have  increased  the  wages  of  the 
drivers,  and  at  the  same  time  the  number  of  customers  served  by  each 
driver. 

(e)  In  the  meantime,  the  company  has  prospered  financially  (stock  is 
three  times  its  par  value). 

(/)  The  farmers  have  been  getting  more  out  of  their  milk  than  ever 
before. 

One  of  the  problems  of  city  delivery  is  that  of  handling  the  "come 
backs"  as  the  undelivered  bottles  of  milk  are  called.  After  milk  has 
been  hauled  about  the  city  in  midsummer  it  has  usually  acquired  a  high 
temperature  and  bacterial  changes  have  started  in  it.  Consequently  it 
should  not  make  another  trip  on  the  delivery  wagon;  nevertheless  some 
dealers  repasteurize  it  and  send  it  out  again.  The  more  particular 
dealers  utilize  such  milk  by  making  it  into  butter  and  cheese.  The  milk 
code  should  prohibit  the  former  practice  and  every  inspector  should  make 
it  a  point  to  know  how  this  part  of  the  milk  business  is  handled. 

Bookkeeping. — Since  every  dealer  is  engaged  in  the  purchase  and  sale 
of  milk  a  system  of  bookkeeping  is  necessary.  The  larger  firms  have 
their  accounts  to  keep  with  the  individual  dairymen  from  whom  they 
buy  milk,  with  the  railroads  which  transport  it  and  with  the  customers 
to  whom  they  sell  at  wholesale  and  retail.  Besides,  an  account  should  be 


358 


CITY  MILK  SUPPLY 


kept  of  the  expenses  of  running  the  country  branch  and  main  plants. 
There  should  also  be  a  system  of  cost  accounting  so  that  the  expense  of 
carrying  on  the  different  parts  of  the  business  may  be  known.  This  sort 


MONTH  OF 
MR. 

i<n 

mAm?HNT  ASHUELOT    DAIRY     CO. 

MONADNOCK,   N.H. 

DATE 

MILK  LEFT 

CREAM  LEFT 

co 

3P 

^ 

CO 

ta 
»  = 

h- 

TICKETS  SOLD 

CASH 
REC'DONACCT. 

QT8 

PTS 

PTS 

%PTS 

CASH 

CREDIT 

1 

2 

3 

4 

^^—<. 

-»__--  —  ' 
—  —-^•* 

p^J 

rH 

rH 

-  —  '  J. 

r==^=\ 

p=^=^j 

^==^===^===^=^ 

30 

31 

TOTAL 

FIG.  50.— Tally  card. 

of  thing  is  new  and  very  few  concerns  practice  it.     The  larger  firms  ap- 
preciate the  importance  of  keeping  accounts  but  many  of  the  small  men 


CJ 
ROUT 

LSH   SHEET   ASHUELOT   DAIRY   CO. 

MONAD  NOCK  N.H. 

E  DATE 

PAGE             (FORM  P)                AMOUNT 

=^d 

^_^__ 

__^___  ,  ^__ 

^^ 

*"      •  — 

-^  •  r 

I  '  ""1 

r  •  ' 

FIG.  51.— Cash  sheet. 

who  are  both  producing  and  selling  their  own  milk  do  not  and  the  conse- 
quence is  that  their  losses  from  bad  accounts  and  slack  methods  of  pur- 
chasing are  severe.  Even  when  close  attention  is  paid  to  collections 


THE  MILK  CONTRACTOR 


359 


some  loss  is  incurred  through  customers  moving  away  and  leaving  small 
unpaid  accounts  that  are  not  worth  the  expense  of  collecting,  etc. 


ASHUELOT    DAIRY    CO.     MONADNOCK,  N.H. 
REQUISITION  ON  COLD  STORAGE  FOR  MILK  AND  CREAM 

AND 

MILK  AND  CREAM  DELIVERY  REPORT 

Date,                                                 191               n™^  No.      1 

Milk 

Cream 

Double  Cream 

Butter  Milk 

| 

1 

\ 

3 

i 

i 

I 

OUT 

Gals. 

Qts- 

Pis. 

HPts 

Gals. 

Ots. 

Pts. 

«Pts. 

Gills 

Pts. 

HPts 

Gills 

(>t8. 

Pts. 

1st 

3nd 

|  RETURNED 

Cream 

55 

Bottles 
lit 

Bottles 
2nd 

MILK 

Received, 

CREAM 

Received, 

Dbl.CREA5I  Gal 
Received, 

Pts. 

BUTTERMILK 

Received, 

Ciul 

Pts. 

Beturned, 

Returned, 

Returned, 

Returned, 

Lost  or  Gained 

Lost  or  Gained 

Lostor 
Gained 

Lost  or 
Gained 

Sold. 

Sold, 

Sold, 

Sold. 

Cash  received  from  Customers.  £ 

?  Ticl 

RA< 

Lets. 

.    ( 

Dhecked  b  j 
ELOT  DAJ 

r 

r 

;eived  for  A8HE 

JUT  CO. 

as  bier 

-  Driver, 

FIG.  52.  —  Driver's  requisition  on  cold  storage  room. 

SPECIAL  ORDER  SLIP 

ASHUELOT  DAIRY   CO. 

Deliver  to                       WWAMOCI.  N.H. 

nr 

St                         *fn 

Order  Received 

To  be  Delivered 

Order 

5.30P.M.  1  Feb. 

3  Feb. 

IQt. 

Milk 

Grade  A 

Grade  B 

Cream 

Single 

HPint 

Double 

IQt. 

Buttermilk 

FIG.  53.— Special  order  slip. 

.There  are  two  common  ways  of  keeping  account  of  the  retail  business, 
namely,  by  means  of  tickets  and  by  the  driver's  tally  sheet  or  route 


360 


CITY  MILK  SUPPLY 


book.  Tickets  are  generally  sold  at  so  many  for  a  dollar  or  some  other 
sum  and  they  usually  call  for  a  certain  amount  of  milk  or  cream.  The 
purchaser  drops  tickets  for  the  amount  of  milk  needed  in  an  empty  milk 


A8HUELOT  DAIRY  CO. 
DUMP   ROC 

-  MOiXADNOCK,  N.H. 
M  REPORT 

Date 

IN 

OUT 

Milk  from  Cars 

To  Milk  Room..  __           

«        .,     Routes 

..         .<     Milk  Room  (overflow) 

Ret'd  to  Farmers  

..     Pedlers 

,.     Modified  Milk 

Skim  on  Hand. 

Skim  to  Milk  Room 

«i      from                                            -  

Curd  Room  

Cars.  ._ 

Left  Over   

Signed. 

FIG.  54. — Dump  room  report. 

bottle  and  leaves  it  on  the  doorstep  for  the  driver  who  fills  the  order  when 
he  comes  along.  The  system  has  the  advantage  of  reducing  business  to 
practically  a  cash  basis  as  long  as  competition  does  not  introduce  the 


ASHUELOT  DAIRY  CO.  •  MO^ADNOCK,  N,H. 
DAIRY  REPORT 

Date 

Patron 

Not  Full 

Sour 

Bitter 

Frozen 

Ole  Grimes 
>    Dad  Pevear 
Caesar  Rice 

_—  -—  •  *^^—  —  -*  —  1-^— 

^—  ^zr^-*—  -—  ^r^—  

1 
^=^=^ 

1 

prr^^r 

Si 

pned 

FIG.  55. — Dairy  report. 

custom  of  trusting  people  for  tickets.  Since  people  run  out  of  tickets 
the  driver  has  to  carry  a  cash  sheet  to  record  occasional  and  extra  sales. 
The  great  disadvantage  of  the  ticket  system  is  its  uncleanliness  and  some 


THE  MILK  CONTRACTOR 


361 


ASHUELOT  DAIRY  CO.  -  JMONADNOCK,  N.H. 
PLATFORM  REPORT 

SOUHEGAN    CARS 

Car  No. 

Cans  Milk 
on  Car 

Cans  Milk 
to  Milk  Room 

Cans  Skim 
on  Car 

Cans  Cream 
on  Car 

KEENE    CARS 

Car  No. 

Cans  Milk 
on  Car 

Cans  Milk 
to  Milk  Room 

Cans  Skim 
on  Car 

Cans  Cream 
on  Car 

HANOVER    CARS 

Car  No. 

Cans  Milk 
on  Car 

Cans  Milk 
to  Milk  Room 

Cans  Skim 
on  Car 

Cans  Cream 
on  Car 

WASHINGTON   CARS 

Car  No. 

Cans  Milk 
on  Car 

Cans  Milk     - 
to  Milk  Room 

Cans  Skim 
on  Car 

Cans  Cream 
on  Car 

GREENFIELD     CARS 

Car  No. 

Cans  Milk 
on  Car 

Cans  Milk 
to  Milk  Room 

Cans  Skim 
on  Car 

Cans  Cream 
on  Car 

FIG.  56. — Platform  report. 


362 


CITY  MILK  SUPPLY 


In  Account  with  ASHUELOT  DAIRY  CO. 

MONADNOCK 

JSEVY  HAMPSHIRE 


Creamery  deliveries 
Bacteria  average 


lbs.= 


.  gals.  @ i 


For  Tuberculin  testing  of  Herd- 


Less  for  Skim  MUk  $ 

««  $ 

Average  test @ <i 


unit 


Check  herewith  to  balance, 


Payment  for  month 
ending 


FIG.  57. — Statement  to  producers. 


ASHUELOT  DAIRY  CO.     MONADNOCK,  N.H, 

111  account  with 


For    MILK        Month  ending.__ 

Account  rendered Gals. 

Corrected  f or .         _ « < 


Less  for  Cans  Washed - ®     1^       $. 

(i     ((    Tags    @    10^   per  100 

a      ((   Freight  on  Returns 

n      «    Cans  Repaired 


Check  herewith  to  balance,    $. 


FIG.  58.— rStatement  to  producers. 


THE  MILK  CONTRACTOR 


363 


slight  danger  it  has  of  spreading  contagion.  Tickets  should  be  printed 
on  cheap  paper  and  be  used  but  once.  Unfortunately  ^ they  are  often 
printed  on  heavy  paper  board  and  used  again  and  again,  till  they  become 
nasty  and  conceivably  they  may  also  become  infected  from  being  held 
in  people's  mouths  and  from  being  fingered  by  diseased  persons  and  bacil- 
lus carriers.  These  considerations  have  led  some  cities  to  forbid  the  use 
of  tickets. 


All  Weekly  Bills  run  from  Sunday  to  Saturday  Inclusive 

Bill  No_ 

Week  No Monadnock,  N.H~ 

Mr. 

ASHUELOT  DAIRY   CO. 
M01VADNOCK,  JV.H. 

""  $  Cts.      > 

Delivered  in  month  of.. 

H       from  Sunday.___:to  Sat 

BILL    RENDERED 

..Pts.,Qts.,Gal.,Jersey  Milk. 
___Pts.,Qts.,Gal.,  Cream.. 

^    Lbs^Butter-. 

p 

-__Bottles  Sterilized  or  Pasteurized  MilJc_- 

__-Buttermilk .Curd- ..^ 

Ots.,lceCreajn _  v 


Total. 


Received  Payment, 


FIG.  59. — Statement  to  customers. 

The  tally-card  and  cash-sheet  system  (Figs.  50  and  51)  is  kept  in  the 
form  of  a  loose-leaved  book  that  the  driver  carries  with  him  and  that  is 
used  to  record  the  deliveries  of  milk,  cream,  etc.,  the  bottles  returned 
and  the  cash  receipts.  Daily  on  his  return  from  the  trip  the  driver  casts 
up  the  tally  sheet  and  makes  returns  to  the  main  office  which  renders 
weekly  or  monthly  statements  to  the  customers  either  by  mail  or  more 
usually  by  the  driver  who  also  makes  collections.  In  the  case  of  whole- 
sale customers  a  tally  sheet  is  usually  posted  at  the  place  of  business 


364 


CITY  MILK  SUPPLY 


and  the  amounts  are  entered  thereon  as  deliveries  are  made,  statements 
being  rendered  monthly. 

The  delivery  wagon  is  loaded  according  to  a  requisition  made  on  the 
cold  storage  room  on  some  such  form  as  Fig.  52,  by  the  driver  who  is 
responsible  for  what  is  sent  out  and  who  makes  an  accounting  for  it  all 
on  his  return. 

In  the  general  office  a  record  is  kept  on  forms  such  as  Fig.  53,  of  special 
orders  received  by  telephone  and  these  are  turned  over  to  the  proper 
driver  for  delivery. 

In  the  large  milk  plants  dump-room  reports  (Fig.  54),  dairy  reports 
(Fig.  56),  and  platform  reports  (Fig.  56)  are  kept.  To  the  producers, 
statements  such  as  forms  Fig.  57  and  Fig.  58,  are  rendered,  and  those  to 
customers  on  forms  similar  to  Fig.  59. 

In  addition  to  all  this,  there  is  the  bookkeeping  for  the  manufacturing 
departments,  for  the  purchasing  departments  and  for  the  accounts  with 
the  several  employees  so  that  the  expense  of  maintaining  the  division  of 
accounts  is  a  considerable  item  in  the  ultimate  cost  of  getting  milk  to  the 
consumer. 

Retail  Price  of  Milk. — The  final  question  is,  at  what  price  can  milk 
be  delivered?  The  price  varies  but  not  to  so  great  an  extent  as  might 
be  expected.  Table  113,  compiled  in  the  first  6  months  of  1916,  gives 
the  average  retail  price  per  quart  of  milk  in  105  cities  in  different  parts 

TABLE  113. — AVERAGE  RETAIL  PRICE  OF  MILK  IN  CENTS  PER  QUART  IN  105  CITIES  OP 

THE  UNITED  STATES 


New  England  States 

Middle  Atlantic  States 

South  Atlantic  States 

City 

Price 

City 

Price 

City                                           Price 

Bangor,  Me  
Boston,  Mass  
Burlington,  Vt.  .  .    . 

8 
9 
8 
9 
8 
9 
9.5 
9 
9 

8.72 

Albany,  N.  Y. 

8 

Ashville,  N.  C  
Atlanta,  Ga  
Baltimore,  Md  
Charleston,  S.  C  
Columbia,  S.  C  
Fredericksburg,  Va.  . 
Jacksonville,  Fla.  .  .  . 
Macon,  Ga 

10 
10 
9 
11.5 
12.5 
.  8 
12.5 
10 
12.5 
10 
10 
12 
9 
5 
8 
10 
10.00 

Altoona,  Pa  
Binghamton,  N.  Y. 
Buffalo,  N.  Y  
Erie,  Pa     . 

.   9 
.   9 

.   8 

7 

Fall  River,  Mass  
Manchester,  N.  H..  .  . 
New  Haven,  Conn  .  .  . 
Portland,  Me  
Providence,  R.  I  
Springfield,  Mass.  .  .  . 

Average  

Montclair,  N.  J  
Newark,  N.  J  
New  York,  N.  Y.  .  .  . 
Philadelphia,  Pa.  ... 
Pittsburgh,  Pa  
Scranton,  Pa.  .  . 

.10 
.   9 
.   9 
.   8 
.10 
.   9 
8 

Pensacola,  Fla  
Richmond,  Va  
Roanoake,  Va  
Savannah,  Ga 

Syracuse,  N.  Y.. 

Trenton,  N.  J  

Watertown,  N.  Y.  .  . 

Average 

.   8 
.   7 

8  50 

Washington,  D.  C.  . 
Wheeling,  W.  Va.... 
Wilmington,  Del.  .  .  . 
Wilmington,  N.  C.  .  . 
Average 

THE  MILK  CONTRACTOR 


365 


East  North  Central  States 

West  North  Central  States 

East  South  Central  States 

City 

Price 

City 

Price 

City 

Price 

Chicago,  111  
Cincinnati,  O  
Cleveland,  O  
Detroit,  Mich  
Eau  Claire,  Wis.  .  . 
Indianapolis,  Ind... 
Joliet,  111  

..   8 
..   8 
..   8 
..   8 
..   7 
..   8 
..   8 
..   7 
7 
..10 
..   7 

..  7  77 

Aberdeen,  S.  D  
Davenport,  la  
Des  Moines,  la  
Dubuque,  la  
Duluth,  Minn. 

.   7 
.   8.5 
.   8 
.   8.5 
10 
8 
.   9 
.   7 
8 
8 
8 
7.5 
8.33 
9 
8.20 

Birmingham,  Ala.  . 
Chattanooga,  Tenn. 
Corinth,  Miss 

.10 
..10 
10 

Lexington,  Ky  
Louisville,  Ky. 

.10 
10 

Fargo,  N.  D  
Kansas  City,  Mo.  .  . 
Lawrence,  Ks  
Manhattan,  Ks  
Omaha,  Neb  
St.  Louis,  Mo  
St.  Paul,  Minn. 

Macon,  Miss  

.10 

Memphis,  Tenn.  ... 
Mobile,  Ala  
Nashville,  Tenn.  .  .  . 
Sheffield,  Ala  

Average   .  . 

.10 
.10 
.10 
.10 

10  00 

Madison,  Wis  
Milwaukee,  Wis.  .  . 
Springfield,  111  
Springfield,  O  

Average  

Wichita,  Ks  

Topeka,  Ks  
Average 

West  South  Central 

States 

Mountain  States 

Pacific  States 

City 

Price 

City 

Price 

City 

Price 

Dallas,  Tex 

10 

Albuquerque,  N.  M. 
Boise,  Id  
Butte,  Mont. 

10 
8.33 
10 
9 
.  7.5 
8.33 
10 
8.33 
-8.33 
10 
8.33 

8.92 

Corvalis,  Ore  
Fresno,  Cal  
Los  Angeles,  Cal. 

.   9 
.   8.33 
9 

Fayetteville,  Ark  .  . 
Galveston,  Tex  
Little  Rock,  Ark.  .  . 
Muscogee,  Okl  
New  Orleans,  La.  .  . 
San  Antonio,  Tex.  . 

Average   . 

..   8.5 
..10 
.  .10 
..   9 
..10 
..10 

9  64 

Cheyenne,  Wyo  
Colorado  Springs,  Col 
Denver,  Col  
Helena,  Mont  
Phenix,  Ariz. 

Portland,  Ore  
Salem,  Ore.  .  . 

.   9.5 
8.33 

Sacramento,  Cal.  .  . 
San  Diego,  Cal  
San  Francisco,  Cal.. 
Seattle,  Wash  
Spokane,  Wash.  .  .  . 
Takoma,  Wash  
Walla  Walla,  Wash. 
Yakima,  Wash  
Average  

.   8.33 
.10 
.10 
.   9 
.12.5 
.   9 
.   8 
.   8.5 
.   9.17 

Reno,  Nev  
Roswell,  N.  M  
Salt  Lake  City,  Utah 

Average 

of  the  United  States.  The  average  price  paid  in  these  cities  was  8.98 
cts. ;  the  minimum  average  price  paid  in  any  one  city  was  5  cts.  and  the 
maximum  12.5  cts. 

Sources 

HAGGARD.  "Rural  Denmark  and  Its  Lessons,"  1913. 

HINMAN,  "Butterfat  Variation  in  Indianapolis  Milk,"  Hoard's  Dairyman,  vol.  48, 

Aug.  1,    1913. 
PECK,  "The  Problem  of  Obtaining  Milk  for  large  cities  and  the  Equalization  between 

Supply  and  Demand,"  Proc.  6th  Annual  Convention  of  the  International  Milk 

Dealers'  Association,  pp.  75-79,  1913. 


366  CITY  MILK  SUPPLY 

VAN  SLYKE,  "Modern  Methods  of  Testing  Milk  Products,"  1913. 
SAVAGE,  "Milk  and  the  Public  Health,"  1912. 
MICHELS,  "Market  Dairying  and  Milk  Products,"  1912. 
ROSENAU,  "The  Milk  Question,"  1912. 
MARSHALL,  "Microbiology,"  1912. 
WARD,  "Pure  Milk  and  the  Public  Health,"  1909. 
DILLON,  "The  Milk  Problem,"  1916. 

KELLY,  "The  Need  for  Medical  Inspection  of  Employees  who  are  Engaged  in  the  Pro- 
duction and  Handling  of  Milk,"  4th  Annual  Report  of  the  International  Asso- 
ciation of  Dairy  and  Milk  Inspectors,  pp.  81-86,  October,  1915. 
CAMPBELL  "Medical  Inspection  of  Certified  Dairies,"  III.  Med.  Jour.,  vol.  28,  No.  2, 

pp.  90-93,  August,  1915. 

BAHLMAN,  "Milk  Clarifiers,"  Am.  Jour.  Public  Health,  vol.  6,  No.  8,  p.  854,  1916. 
HINKELMAN,  "Micro-organic  Weight,"  1915.     Illinois  Med.  Jour.,  vol.  29,  No.  3,  p. 

202,  1916. 
McCLiNTOCK,  "Further  Investigations  upon  Clarification  of  Milk."     The  Milk  Trade 

Journal,  September,  1916,  p.  64. 
HAMMER,  "Studies  on  the  Clarification  of  Milk,"  Res.  Bull  28,  Ag.  Expt.  Sta.,  Iowa 

State  College  of  Ag.  and  Mech.  Arts,  1916. 
HARDING  and  ROGERS,  "The  Efficiency  of  a  Continuous  Pasteurizer  at  Different 

Temperatures,"  Bull.  172,  N.  Y.  Ag.  Expt.  Sta.,  1899. 
SAMMIS  and  BRUHN,   "The  Manufacture  of  Cheese  of    the    Cheddar  Type  from 

Pasteurized  Milk,"  Bull.  165,  Bureau  Animal  Industry,  U.  S.  Dept.  Ag.,  1913. 
MORTENSEN,  GAESSLER,  COOPER  and  HAMMER,  "The  Pasteurization  of  Cream  for 

Butter  Making,"  Bull.  156,  Iowa  Sta+e  College  Ag.  Expt.  Sta.,  1914. 
PEASE,  "The  Sanitary  Significance  of  Bacteria  in  Milk,"  Proc.  6th  Annual  Convention 

of  the  International  Milk  Dealers'  Association,  1913. 
STRAUS,  L.  G.,  "Disease  in  Milk— The  Remedy  Pasteurization,"  1913. 
RUPP,  "Chemical  Changes  Produced  in  Cow's  Milk  by  Pasteurization,"  Bull.  166, 

Bureau  Animal  Industry,  U.  S.  Dept.  Ag.,  April,  1913. 

DOSCH,  "The  Pasteurized  Milk  Fraud,"  Pearson's  Magazine,  December,  1910. 
ROTCH,  "The  Pasteurization  of  Milk  for  Public  Sale,"  Am.  Jour.  Public  Hygiene,  vol. 

17,  No.  2,  May,  1907. 
DE  SCHWEINITZ,  "The  Pasteurization  and  Sterilization  of  Milk,"  Yearbook,  U.  S.  Dept. 

Ag.,  1894. 
AYRES  and  JOHNSON,   "The  Bacteriology  of  Commercially  Pasteurized  and  Raw 

Market  Milk,"  Bull.  126,  Bureau  Animal  Industry,  U.  S.  Dept.  Ag. 
ROSENAU,  "Pasteurization,  Its  Advantages  and  Disadvantages,"  Circ.  153,  Bureau 

Animal  Industry,  U.  S.  Dept.  Ag.,  1910. 

WELD,  "  George  M.  Oyster  Jr.  Baby  Milk  Philanthropy,"  1912. 
COLLAWAY,  "  The  Pasteurization  of  Milk,"  The  Milk  Trade  Journal,  vol.  3,  Nos.  8  and  9, 

October  and  November,  1915. 
HANSEN  and  PARKER,  "Typhoid  Fever  in  Rockford,  111.,"  Jour.  Infect.  Diseases,  vol. 

16,  No.  1,  p.  20,  January,  1915. 
SMITH,  THEOBALD,  "The  Thermal  Death  Point  of  Tubercle  Bacilli  in  Milk  and  Some 

Other  Fluids,"  Jour.  Exper.  Med.,  vol.  4,  pp.  217-233,  1899. 
RUSSELL  and  HASTINGS,  "Thermal  Death  Point  of  Tubercle  Bacilli  Under  Commercial 

Conditions,"  Univ.  Wis.  Ag.,  Expt.  Sta.,  17th  Annual  Report,  1900. 
ROSENAU,  "The  Thermal  Death  Points  of  Pathogenic  Micro-organisms  in  Milk," 

Hygienic  Lab.  Bull.  42,  Public  Health  and  Marine  Hospital  Service,  January, 

1908. 
LUMSDEN,  "The  Milk  Supply  of  Cities  in  Relation  to  the  Epidemiology  of  Typhoid 

Fever,"  Bull.  41,  Public  Health  and  Marine  Hospital  Service,  pp.  151-159,  1908, 


THE  MILK  CONTRACTOR  367 

BOLDUAN,  "Typhoid  Fever  in  New  York  City,"  Department  of  Health  of  New  York 

City,  Monograph  Series  No.  3,  August,  1912. 
GEIGER  and  KELLY,  "Pasteurization  of  Milk  Supplies  as  a  Protection  Against  Typhoid 

Fever,"  Jour.  A.  M.  A.,  vol.  66,  No.  4,  Jan.  22,  1916. 
HESS,  "Infantile  Scurvey:  III.  Its  Influence  on  Growth  (length  and  weight),"  Am. 

Jour,  of  Diseases  of  Children,  vol.  12,  pp.  152-165,  August,  1916. 
SCHORER  and  ROSENAU,  "Tests  of  the  Efficiency  of  Pasteurization  under  Practical 

Conditions,"  Jour.  Med.  Res.,  vol.  26,  No.  1,  April,  1912. 
RUSSELL,  "The  Year's  Progress  of  the  Experiment  Station,"  Bull  250,  Univ.  Wis. 

Ag.  Expt.  Sta.,  April,  1915. 
STURGIS,  "The  Role  of  Dairy  Inspection  in  Safeguarding  a  City's  Milk  Supply," 

Department  of  Health  of  the  City  of  New  York,  Reprint  Series  No.  30,  June, 

1915. 
KILBOURNE,  "Pasteurization  of  Milk  with  Suggestions  as  to  Methods  and  Apparatus 

to  be  Employed,"  Am.  Jour.  Public  Health,  vol.  2,  No.  8,  pp.  626-634.  August, 

1912. 
AYRES,  "The  Pasteurization  of  Milk,"  Circ.  184,  Bureau  Animal  Industry,  U.  S. 

Dept.  Ag.,  1912. 
AYRES,  "Pasteurizing  Milk  in  Bottles  and  Bottling  Hot  Milk  Pasteurized  in  Bulk," 

Bull.  240,  U.  S.  Dept.  Ag.,  July,  1915. 
AYERS,  BOWEN  and  JOHNSON,  "Cooling  Hot-bottled  Pasteurized  Milk  by  Forced 

Air,"  Bull.  420,  U.  S.  Dept.  Ag.,  27,  October,  1916. 

KASTLE,  "The  Chemistry  of  Milk,"  Hygienic  Lab.  Bull  56,  pp.  315-425,  1909. 
HUNZIKER,  "Pasteurization  of  Market  Milk,"  The  Milk  Trade  Journal,  pp.  36  and  44, 

June,  1916. 
KILBOURNE,  "What  Causes  Contribute  to  the  Loss  of  the  Cream  Line,  in  Pasteurized 

Milk  in  Bottles,"  Department  of  Health  of  New  York  City,  Reprint  Series  No. 

27,  April,  1915. 
Jour.  A.  M.  A.,  vol.  63,  No.  1,  p.  50,  July  4,  1915,  "Decision  Upholding  Automatic 

Temperature  Control." 
AYRES  and  JOHNSON,  "A  Study  of  the  Bacteria  that  Survive  Pasteurization,"  Bull. 

161,  Bureau  Animal  Industry,  U.  S.  Dept.  Ag.,  1913. 
AYRES  and  JOHNSON,  "Ability  of  Colon  Bacilli  to  Survive  Pasteurization,"  Jour.  Ag. 

Res.,  vol.  3,  No.  5,  pp.  401-416,  Feb.  15,  1915. 
AYRES  and  JOHNSON,  "Ability  of  Streptococci  To  Survive  Pasteurization,"  Jour.  Ag. 

Res.,  vol.  2,  No.  4,  pp.  321-330,  1914. 
THOM  and  AYRES,  "Effect  of  Pasteurization  on  Mould  Spores,"  Jour.  Ag.  Res.,  vol.  6, 

No.  4,  1916. 
DAVIS,  "  Bacteriologic  Study  of  Streptococci  in  Milk  in  Relation  to  Epidemic  Sore 

Throat,"  Jour.  A.  M.  A.,  vol.  58,  No.  24,  pp.  1852-1854,  June  15,  1912. 
HAMBURGER,  "The  Baltimore  Epidemic  of  Septic  Sore  Throat  and  its  Relation  to  the 

Milk  Supply,"  Bull  Johns  Hopkins  Hospital,  vol.  24,  No.  263,  pp.  1-11,  1913. 
NORTH,  "Pasteurization  of  Milk  in  the  Bottle  on  a  Commercial  Scale,"  Med.  Rec., 

July  15,  1911. 
CARTER,  "Pasteurization  of  Milk  in  the  Sealed  and  Final  Package,"  Jour.  Am.  Public 

Health  Assn.,  vol.  1,  No.  9,  pp.  664-668,  September,  1911, 
HAMMER,  "The  Pasteurization  of  Milk  in  the  Final  Package,"  Bull.  154,  Iowa  State 

College  Ag.  Expt.  Sta.,  November,  1914. 
Report  of  the  Board  of  Commissioners  of  Agriculture  and  Forestry  of  the  Territory 

of  Hawaii  for  the  Biennium  Ending  Dec.  31,  1912,  "Milk  Purifying  by  Electri- 
city," pp.  185-187. 
LEWIS,  "Destruction  of  Bacteria  in  Milk  by  Electricity,"  Jour.  Board  of  Ag.,  vol.  22, 

No.  12,  pp.  1229-1239,  1916. 


368  CITY  MILK  SUPPLY 

FORD  and  PRYOR,  "Observations  Upon  the  Bacteria  in  Milk  Heated  to  Various 

Temperatures,"  Butt.  Johns  Hopkins  Hospital,  vol.  25,  No.  283,  pp.  270-278, 

September,  1914. 
PRYOR,  "On  the  Presence  of  Spore-bearing  Bacteria  in  Washington  Market  Milk," 

Bull  Johns  Hopkins  Hospital,  vol.  25,  No.  283,  pp.  276-278,  September,  1914. 
LAWRENCE  and  FORD,  "Studies  on  Aerobic  Spore-bearing,  Non-pathogenic  Bacteria," 

Part  I,  "Spore-bearing  Bacteria  in  Milk,"  Jour,  of  Bacteriology,  vol.  1,  No.  3, 

pp.  373-417,  1916. 
BROWN,  H.  R.,  "A  Study  of  the  Spore-bearing  Bacteria  in  Market  Milk,"  41st. 

Annual  Report  Massachusetts  State  Board  of  Health,  pp.  632-667. 
SHIPPEN,  "  Common  Organisms  in  Heated  Milk — Their  Relation  to  Their  Reactions," 

Bull.  Johns  Hopkins  Hospital,  vol.  26,  No.  293,  July,  1915. 
Report  of  Committee  on  City  Milk  Plant  Inspection  of  International  Association  of 

Dairy  and  Milk  Inspectors,  The  Creamery  and  Milk  Plant  Monthly,  vol.  4,  No.  3, 

No.  15,  p.  17. 

"  Valid  Regulations  of  the  Sale  of  Milk,"  Jour.  A.  M.  A.,  vol.  63,  No.  1,  p.  54,  1914. 
AYRES  and  JOHNSON,  "The  Destruction  of  Bacteria  in  Milk  by  Ultraviolet  Rays," 

Wash.  Acad.  of  Sci.,  vol.  3,  No.  5,  pp.  160-164,  March,  1915. 
HOUGHTON  and  DAVIS,  "A  Study  of  the  Germicidal  Action  of  the  Ultraviolet  Rays," 

Am.  Jour.  Public  Health,  vol.  4,  No.  3,  pp.  224-240,  March,  1914. 
AYRES,  "The  Present  Status  of  the  Pasteurization  of  Milk,"  Bull.  342,  U.  S.  Dept. 

Ag.,  Jan.  8,  1916. 
MORRIS,  "Shipment  of   Milk    in   Glass   Jars,"   Jour.  Franklin  Institute,  vol.  109, 

No.  649,  Jan.,  1880. 

Dairy  Division,  Bureau  Animal  Industry,  U.  S.  Dept.  Ag.,  Milk  Plant  Letters  1-27. 
DOANE,  "The  Disinfectant  Properties  of   Washing   Powders,"  Bull.  79,  Md.*Ag. 

Expt.  Sta.,  January,  1902. 
WHITTAKER  and  MOHLER,  "The  Sterilization  of  Milk  Bottles  with  Calcium  Hypo- 

chlorite,"  Am.  Jour.  Public  Health,  vol.  2,  No.  4,  pp.  282-287,  April,  1912. 
BOWEN,  "The  Application  of  Refrigeration  to  the  Handling  of  Milk,"  Bull.  98,  U.  S. 

Dept.  Ag. 

AYRES,  Pasteurization  Bull.  342,  U.  S.  Dept.  Ag.,  January,  1916. 
WILLIAMS,  "Use  of  Ice  and  Other  Means  of  Preserving  Food  in  Homes,"  Scientific 

American,  Supplement,  No.  1,983,  Jan.  3,  1911. 
Bo  WEN,  "The  Utilization  of  Exhaust  Steam  for  Heating  Boiler  Feed  Water  and  Wash 

Water  in  Milk  Plants,  Creameries  and  Dairies,"  Circ.  209,  Bureau  Animal  Indus- 
try, U.  S.  Dept.  Ag.,  1913. 
WAY,  "A  Bacteriologic  Comparison  of  Milk  Served  in  Bottles  and  by  the    Dip 

Method,"  The  Cleveland  Med.  Jour.,  vol.  6,  No.  4,  pp.  147-154,  April,  1907. 
FENDER  and  THOMPSON,  "Notes  on  the  Cost  of  Motor  Trucking,"  Vehicle  Res.  Bull. 

2,  Elect.  Eng.  Dept.  Mass.  Inst.  Tech.,  1912. 
THOMSON,  "Relative  Fields  of  Horse,  Electric  and  Gasolene  Trucks,"  Vehicle  Res. 

Bull.  4,  Elect.  Eng.  Dept.  Mass.  Inst.  Tech.,  August,  1914. 
WILLIAMS,  "The  Economic  Problems  of  Milk  Distribution  in  their  Relation  to  Public 

Health,"  Trans.  15th  International  Congress  of  Hygiene  and  Demography,  1912. 
WILLIAMS,  "The  Problem  of  Distribution,"  Proc.  Am.  Assn.  Med.  Milk  Commissions, 

6th,  7th  and  8th  Annual  Conference,  pp.  94-118,  1915. 
H.  P.  HOOD  and  SONS,  "Cost  of  Delivering  a  Quart  of  Milk  to  the  Consumer,"  Hoard's 

Dairyman,  vol.  43,  No.  25,  p.  859,  June  19,  1912. 
KELLY,  "To  Start  in  the  Retail  Milk  Business,"  Hoard's  Dairyman,  vol.  51,  No.  13, 

p.  553,  1916. 


THE  MILK  CONTRACTOR  369 

BOSTON  CHAMBER  OF  COMMERCE,  "Investigation  and  Analysis  of  the  Production, 
Transportation,  Inspection,  and  Distribution  of  Milk  and  Cream  in  New  Eng- 
land," July,  1915. 

ERF,  "Disposal  of  Dairy  and  Farm  Sewage,  and  Water  Supply,"  Bull.  143,  Kan.  Ag. 
College  Expt.  Sta.,  February,  1907. 

FARRTNGTON  and  DAVIS,  "The  Disposal  of  Creamery  Sewage,"  Bull.  245,  Univ.  Wis. 
Ag.  Expt.  Sta.,  February,  1915. 

State  Board  of  Health  of  Wisconsin,  "Purification  Of  Creamery  Waste,"  1913. 


21 


CHAPTER  VII 
CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 

Early  Attempts  at  Control  in  Europe. — Laws  were  enacted  in  Europe 
as  early  as  the  middle  of  the  14th  century  to  prevent  the  sale  of  meat  of 
diseased  animals  but  laws  to  prevent  the  sale  of  impure  milk  came  much 
later.  The  first  English  law  to  deal  w  th  the  quality  of  milk  was  passed 
in  1860  and  merely  prohibited  the  dilution  of  milk  with  water  and  the  use 
of  other  substances  to  conceal  such  dilution.  The  first  rules  to  regulate 
a  city  milk  supply  in  Scotland  were  those  enforced  by  the  Willowbank 
Dairy  of  Glasgow  in  1809  and  the  first  in  England  were  those  of  the 
Aylesbury  Dairy  Co.  which  in  1866  adopted  the  rules  of  the  Scottish 
dairy.  The  Aylesbury  Dairy  Co.  established  two  grades  of  milk;  one  in- 
cluded the  milk  that  was  believed  to  be  fit  for  direct  consumption  and  the 
other  that  which  could  not  be  so  used  and  was,  therefore,  churned  to 
butter.  Prior  to  the  establishment  of  the  Aylesbury  and  other  large 
dairies  milk  was  sold  by  many  men  each  of  whom  had  but  few  cows,  and 
standards  of  his  own,  consequently  the  quality  of  the  milk  was  very  vari- 
able. The  concentration  of  the  business  into  the  hands  of  large  com- 
panies, often  of  a  cooperative  character,  gradually  brought  about  more 
uniform  conditions  and  something  like  standard  milk  quality. 

.  It  does  not  appear  that  city  milk  supply  in  the  United  States  has  been 
directly  influenced  by  the  methods  of  control  developed  in  Europe  but  the 
excellent  principles  of  general  dairying  and  dairy  manufacturing  evolved 
by  the  Danes  and  Dutch  are  appreciated  and  the  success  of  the  Copen- 
hagen Milk  Supply  Co.  and  the  Trifolium  Dairy  have  led  American  dairy 
students,  visiting  Denmark,  to  study  their  methods  carefully. 

Early  Attempts  at  Control  in  the  United  States. — In  the  United  States 
apparently  the  first  law  controlling  the  milk  supply  was  that  passed  by 
the  State  of  Massachusetts  in  1856  prohibiting  the  adulteration  of  milk. 
The  office  of  Boston  Milk  Inspector  was  established  in  1859  and  in  the 
same  year  the  use  of  distillery  slop  as  a  cattle  feed  was  prohibited.  In 
1864  this  law  was  revised,  and  the  use  of  milk  from  diseased  cows  forbidden. 
This  early  Massachusetts  legislation  is  interesting  as  showing  that  from 
an  early  period  there  has  been  a  congested  population  in  Boston  which 
it  has  been  difficult  to  supply  with  milk. 

The  dates  at  which  the  more  progressive  cities  of  the  different  sections 
of  the  United  States  undertook  the  control  of  their  milk  supply  is  shown 
in  Table  114.  In  Table  115  the  facts  recorded  in  Table  114  are  summar- 

370 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


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CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  373 

ized.  It  appears  that  in  the  20  years  from  1885  to  1904  it  was  but  slowly 
that  American  cities  assumed  control  of  their  milk  supplies.  The  early 
efforts  of  inspectors  were  directed  toward  the  suppression  of  skimming 
and  watering  which  had  become  very  common ;  no  city  maintained  regular 
dairy  inspection  until  1895;  from  then  on  the  cities  gradually  took  it 
up  but  it  took  10  years  to  impress  the  country  with  its  importance.  In 
the  five  years  from  1905  to  1909  no  less  than  33  of  the  cities  under  con- 
sideration accepted  it  and  by  1913,  69  per  cent,  of  them  had  done  so. 
It  cannot  be  said  that  the  movement  for  municipal  milk  control  proceeded 
in  a  regular  manner  from  the  older  sections  of  the  country  to  those  that 
were  settled  later.  On  the  contrary  it  was  adopted  wherever  a  city  grew 
to  sufficient  size  to  make  the  supplying  of  it  with  milk  a  difficult  problem. 
In  the  early  years  samples  were  examined  only  for  fats  and  solids ;  bac- 
terial examinations  came  later.  Montclair,  N.  J.,  was  the  first  city  to 
make  regular  bacteriological  examination  of  milk;  most  other  cities  have 
taken  up  this  line  of  work  since  1900. 

In  regard  to  these  tables  it  should  be  stated  that  the  Board  of  Health 
of  New  York  City  in  1873  forbade  the  sale  of  swill-milk,  watered  or 
adulterated  milk  and  in  that  same  year  collected  $2,400  in  fines  from  37 
dealers  who  violated  it.  In  1876  the  Board  adopted  an  ordinance  pro- 
hibiting the  sale  of  watered,  adulterated  milk  or  skimmed  milk.  In 
enforcing  this  law  the  lactometer  was  used  to  determine  the  quality  of  the 
milk  till  1895  when  producers  and  dealers  became  so  proficient  in  beating 
the  instrument  that  the  board  was  compelled  to  set  a  chemical  standard 
and  begin  the  regular  collection  and  analysis  of  milk  samples. 

In  Iowa  since  1892,  the  local  milk  inspection  in  cities  having  a  popula- 
tion of  10,000  or  over,  are  appointed  by  the  State  Dairy  Commissioner 
and  the  courts  hold  the  legislature  has  never  delegated  the  right  to  regu- 
late the  milk  supplies  to  the  cities,  the  power  to  control  being  vested  only 
in  the  State  Dairy  Commissioner.  In  several  of  the  Mountain  States 
the  control  of  milk  supply  is  a  function  of  the  State.  In  Idaho  none  of  the 
cities  undertake  to  protect  their  milk  supplies;  that,  since  May,  1911, 
has  been  done  by  the  State  Department  of  Food,  Drug  and  Hotel  Inspec- 
tion. In  Montana,  since  1912,  the  State  has  had  charge  of  all  milk 
supplies  except  that  of  Butte.  In  Nevada  the  State  Department  of  Food 
and  Drugs  Control  since  Jan.  1,  1910,  has  been  in  charge  of  dairy  in- 
spection and  milk  analysis.  Reno  operates  under  a  special  ordinance 
in  cooperation  with  the  State  Board  of  Health. 

Milk  control  in  the  United  States  has  received  several  impulses  that 
have  visibly  affected  its  course.  Among  the  most  important  of  them  were 
the  invention  of  the  Babcock  test  in  1891  which  gave  an  easy  and  accurate 
way  to  determine  butterfat  in  milk,  the  publication  by  Sedgwick  and 
Batchleder  in  1892  of  the  results  of  their  bacteriological  examination  of 
Boston  milk,  which  brought  the  public  to  a  realization  of  the  importance 


374  CITY  MILK  SUPPLY 

of  dairy  sanitation,  and  the  marketing  of  certified  milk  by  Dr.  Coit  and 
Stephen  Francisco  in  Montclair,  N.  J.,  in  1893,  which  marked  the  demon- 
stration that  it  was  commercially  possible  to  produce  clean  wholesome 
milk.  Other  factors  that  have  influenced  milk  control  are  bovine  tuber- 
culosis and  other  communicable  diseases  of  men  and  animals  that  are 
transmissible  in  milk,  the  belief  that  impure  milk  was  an  important  cause 
of  infant  mortality,  and  pasteurization. 

The  first  milk  inspection  was  started  because  consumers  believed  that 
they  were  not  getting  good  milk  and  medical  men  were  given  charge  of 
inspection  because  it  was  thought  that  watering  and  skimming  milk 
made  it  injurious  to  health.  It  was  because  the  public  regarded  the 
milkman  who  would  jeopardize  the  health  of  infants  and  invalids  by  such 
practices  as  a  despicable  fellow  that  all  who  sold  milk  that  did  not  con- 
form to  the  standards  were  treated  as  criminals  and  the  administration 
of  the  milk  code  in  many  instances  became  tainted  with  viciousness. 
Nowadays  skimming  and  watering  milk  are  regarded  rather  as  robbery 
than  as  an  attack  on  the  consumer's  health  for  while  there  is  some  danger 
that  impure  water  may  be  used  in  adulterating  and  that  filthy  practices 
may  attend  the  skimming,  on  the  whole  there  is  no  reason  for  being  very 
apprehensive  and  it  is  quite  unlikely  that  the  milk  will  be  tampered  with 
to  such  an  extent  that  it  will  in  any  marked  degree  lose  its  nutritious 
properties.  The  real  offense  is  in  defrauding  the  customer,  in  making  him 
pay  whole-milk  prices  for  skimmed  and  watered  milk.  The  recognition 
of  this  fact  and  that  it  is  principally  infected  milk  that  endangers  the  con- 
sumer has  materially  modified  the  conception  of  the  way  the  milk  code 
should  be  administered.  The  persistent  milk  adulterator  should  be  vig- 
orously prosecuted  because  he  is  making  a  living  by  robbing  the  public 
on  the  one  hand  and  by  carrying  on  unfair,  cutthroat  competition  with  his 
business  rivals  on  the  other,  but  the  dairyman  whose  milk  is  watered  by 
his  inferior  cows  or  is  polluted  through  his  ignorance  is  a  fitter  subject 
for  the  dairy  instructor  than  the  police  court  judge.  It  is  the  educative 
side  of  milk  control  that  is  most  important. 

Principles  of  Modern  Milk  Control. — The  modern  concept  of  milk 
control  has  been  cogently  stated  by  Woodward  and  briefly  is  this. 
Those  interested  in  the  milk  business  are  the  consumer,  the  producer,  the 
vendor,  the  inspector  and  the  judge.  The  city  milk  trade  rises  out  of  the 
consumer's  demand  for  milk  and  it  is  his  purse  that  supports  the  whole 
business;  therefore  his  interests  are  paramount.  Broadly  speaking  the 
interests^of  the  consumer  are  those  of  all,  consequently  it  is  possible  to 
handle  thejnilk  business  as  a  community  business.  Were  this  not  done, 
every jnan  would  have  to  make  his  own  contract  for  milk  specifying  its 
quality,  the  conditions  under  which  it  should  be  produced,  the  way  in 
which  it  should  be  delivered  and  having  clauses  permitting  an  agent  of 
the  owner  to  see  that  the  contract  is  carried  out  and  attaching  penalties 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  375 

for  infractions  of  the  agreement.  The  confusion  resulting  from  such  a 
system  would  be  intolerable;  so  the  community  acting  through  the  law- 
making  power  makes  a  contract  or  law  which  establishes  the  quality  of 
the  milk,  the  way  it  shall  be  handled,  etc.  It  places  the  responsibility 
for  seeing  the  law  is  lived  up  to  in  the  hands  of  an  inspector  and  provides 
courts  to  settle  disputes  that  may  arise  between  the  parties  to  the  con- 
tract. It  is  apparent  that  this  contract  or  law  must  be  so  drawn  that  it 
is  fair  to  all.  In  theory  a  law  that  imposes  whimsical  or  arduous  condi- 
tions on  the  vendor  or  producer  will  result  in  high  prices  to  the  consumer 
and  one  that  does  not  protect  the  consumer's  interests  is  likely  to  invite 
slovenly  competition  and  therefore  to  fail  to  protect  the  market  to  the 
dealer.  This  raises  the  question,  what  is  the  object  of  a  milk  ordinance? 
It  is  this,  to  secure  good  clean  milk  for  the  consumer.  Henderson  has 
defined  such  milk  as  that  which,  being  produced  by  practical  dairymen 
from  profitable  cows,  economically  fed,  housed  in  clean  quarters,  milked 
and  attended  by  intelligent  and  well-paid  milkers,  is  promptly  cooled, 
kept  uncontaminated  till  used,  and  is  produced  at  a  cost  which  admits  of 
its  being  sold  at  a  price  which,  while  not  prohibitive  to  the  consumer,  yet 
insures  legitimate  profit.  The  late  G.  M.  Whitaker  said  that  milk  of  good 
quality  should  be  that  with  a  proper  amount  of  food  material,  no  foreign 
substances,  and  no  pathogenic  bacteria  and  that  it  should  come  from 
clean  cows,  in  clean  surroundings.  So  there  should  be  the  following 
standards  for  milk;  food  standards,  bacteriological  standards,  temperature 
standards  and  score-card  standards. 

Food  standards  would  protect  the  public  against  adulteration  and 
should  keep  off  the  market,  milk  of  low  food  value.  Bacterial  standards 
serve  as  a  check  on  the  methods  of  production,  but  do  not  mean  that 
milk  attaining  these  standards  is  free  from  disease  germs.  Temperature 
standards  should  mean  that  the  milk  is  kept  as  near  40°F.  as  possible. 
The  score  card  should  bring  the  dairy  and  dairyman  to  higher  standards. 

In  addition  to  the  postulates  of  Henderson  and  Whitaker  the  writer 
would  ad d  that  the  milk  should  come  from  healthy  cows.  That  the  milk 
of  cows  suffering  from  such  diseases  as  anthrax,  aphthous  fever,  cowpox 
and  some  other  maladies  should  not  be  sold,  probably  all  would  agree, 
but  probably  some  would  permit  the  sale  of  pasteurized  milk  from 
animals  that  failed  to  give  evidence  of  tuberculosis  on  careful  physical 
examination.  In  regard  to  this  matter  it  is  best  to  be  conservative  but 
the  dairy  world  is  probably  slowly  working  toward  a  great  reduction  in 
the  amount  of  tuberculosis  that  will  be  tolerated  in  herds  supplying  the 
city  market  and  possibly  toward  its  ultimate  extinction  and  it  is  the 
writer's  belief  that  well-considered  ordinances  should  exert  pressure  in 
this  direction.  Pasteurization  acts  as  a  palliative  and  not  as  a  cure  of 
the  tuberculosis  problem.  When  properly  supervised,  it  offers  a  high 
degree  of  protection  from  the  disease  but  it  can  never  be  regarded  as 


376  CITY  MILK  SUPPLY 

furnishing  immunity  from  it  and  it  is  to  be  remembered  that  the  more 
heavily  the  herds  are  infected  the  more  likely  is  the  protection  offered 
by  pasteurization  to  fail. 

Federal  Control  of  the  Milk  Supply. — The  object  being  to  secure  for 
the  public,  milk  of  a  character  comparable  to  that  indicated  by  Henderson 
and  Whitaker  the  question  arises  whether  control  of  the  supply  had  best 
be  undertaken  by  Federal,  State  or  municipal  authorities.  Such  power 
as  the  Federal  Government  possesses  to  compel  milk  dealers  to  produce 
safe  clean  milk  is  derived  from  the  Food  and  Drug  Act  which  is  adminis- 
tered by  the  Bureau  of  Chemistry  of  the  Department  of  Agriculture. 
Under  this  Act,  the  Department  has  power  to  request  the  Department  of 
Justice  to  order  prosecutions  or  seizures,  only  in  the  case  of  milk  that 
enters  into  interstate  commerce.  In  this  work  the  Department  does  not 
set  up  standards  but  accepts  those  of  the  city  into  which  the  milk  is 
being  shipped  across  State  lines.  The  Bureau  of  Chemistry,  which  has 
only  a  limited  number  of  inspectors,  does  most  of  its  work  by  cooperating 
with  local  authorities  in  the  case  of  milk  produced  across  a  State  line. 
When  milk  is  found  to  be  adulterated,  it  is,  of  course,  seized.  When  indi- 
cations are  found  that  the  milk  is  not  properly  produced,  and  is  likely 
to  become  dangerous,  the  dairyman  is  warned  to  clean  up  and  is  shown 
how  to  improve  his  milk.  If  he  fails  to  act  on  this  warning,  prosecution 
follows. 

The  Food  and  Drug  Act  applies  to  milk  imported  to  the  United  States 
from  foreign  countries  and  according  to  its  provisions  the  milk  must 
conform  to  the  standards  of  the  nation  from  which  it  originates  as  well  as 
to  those  of  the  United  States.  Dairy  products  which  do  not  meet  these 
standards  are  denied  entry.  The  U.  S.  Department  of  Agriculture  and 
the  health  officials  of  Canada  cooperate  in  the  attempt  to  secure  the 
production  and  shipment  of  sanitary  milk.  Producing  dairies  must  re- 
ceive a  well-balanced  score  of  50  on  the  basis  of  100  possible  points.  To 
secure  this  score  a  dairy  must  meet  certain  Canadian  requirements  as  to 
sanitation  and  handling  of  the  milk,  that  are  very  similar  to  those  that 
would  be  required  to  make  such  a  score  on  the  " official"  score  card  in 
use  in  the  United  States.  Furthermore,  the  milk  must  neither  be  mis- 
branded  nor  adulterated  within  the  meaning  of  the  Act.  Milk  that  meets 
Canadian  requirements  also  meets  those  of  the  United  States. 

Such  is  the  statement  of  the  Department  of  Agriculture  with  reference 
to  its  own  work.  Evidently  the  Department  has  no  jurisdiction  over 
intrastate  milk  business  and  it  is  patent  that  a  bureau  with  a  limited 
number  of  inspectors  can  exercise  only  a  nominal  control  over  the  great 
bulk  of  milk  that  enters  into  interstate  commerce.  Nevertheless  the 
Department  has  done  important  work  in  studying  conditions  that  obtain 
in  particular  districts  and  in  assisting  local  authorities  of  cities  receiving 
considerable  quantities  of  milk  from  extrastate  sources  to  increase  the 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  377 

cleanliness  and  stop  the  adulteration  of  such  milk.  In  campaigns  to 
improve  such  supplies  the  effort  is  made  to  teach  dairymen  better  methods 
of  production. 

State  Control  of  the  Milk  Supply. — It  has  been  mentioned  that,  in 
Idaho,  Montana  and  Iowa,  control  of  the  milk  supply  is  exercised  solely  by 
the  State  which  acts  through  variously  constituted  State  boards  or  a  State 
Dairy  Commissioner.  None  of  these  States  have  large '  cities,  conse- 
quently the  regulation  of  the  milk  supply  presents  a  somewhat  different 
problem  than  in  those  States  with  large  urban  populations  that  are  sup- 
plied by  a  specialized  highly  organized  milk  industry.  Control  of  the 
milk  supply  may  be  put  in  the  hands  of  the  State  for  the  good  reason 
that  the  interests  of  the  people  and  the  industry  are  best  served  by  a 
moderate  amount  of  supervision  mostly  of  an  advisory  character  or  for 
the  unworthy  one  that  the  granger  element  wishes  to  keep  cities  from 
enacting  milk  ordinances  that  dairymen  regard  as  inimical  to  their  inter- 
ests. In  many  States,  as  for  instance  New  York,  New  Jersey  and  Illi- 
nois, the  State  Boards  of  Health  maintain  laboratories  and  a  force  of 
inspectors  in  the  effort  to  improve  both  city  milk  supplies  and  dairy 
manufactures  and  often  pay  particular  attention  to  the  milk  supplies  of  the 
smaller  cities  because  their  purity  is  commonly  inadequately  protected. 

Sanitarians  are  not  agreed  as  to  the  wisdom  of  State  control  of  the 
milk  supply.  The  magnitude  of  the  problem  is  an  all  but  insuperable 
obstacle  to  dealing  with  it  successfully  in  this  manner.  There  are  thou- 
sands of  dairies  in  a  State  and  to  inspect  them  so  often  as  to  be  assured 
that  the  ordinary  precautions  that  are  known  to  be  essential  to  the  pro- 
duction of  clean  milk  are  employed  would  require  a  far  larger  force  of 
inspectors  than  any  State  has  ever  contemplated  employing.  Some  of 
those  most  experienced  in  the  enforcement  of  pure  food  laws  are  con- 
vinced that  the  skimming  and  watering  of  milk  can  be  kept  down  only 
by  sampling  and  analyzing  the  milk  of  the  different  dealers  so  frequently 
that  the  dishonest  ones  will  not  care  to  take  the  risk  of  being  detected  in 
fraud.  That  sort  of  supervision  may  be  necessary  with  city  milk  sup- 
plies but  it  would  probably  be  unwise  and  certainly  would  be  impossible 
to  attempt  to  maintain  the  milk  standards  of  the  entire  State  in  this  way. 
These  officials  point  out  that  the  efforts  of  the  States  to  eradicate  tuber- 
culosis by  legislation  have  not  been  conspicuously  successful.  Therefore, 
they  believe  that  it  is  futile  for  the  State  to  attempt  to  exercise  even  so 
much  as  a  supervisory  control  of  the  milk  supply.  They  would  have  it 
do  a  minimum  of  analytical  work  and  inspection  and  confine  its  efforts 
toward  improving  the  milk  supply,  to  utilizing  its  numerous  avenues  of 
publicity  to  educate  the  citizens  on  all  phases  of  the  milk  question  and 
in  assisting  municipalities  to  draw  up  sensible  workable  ordinances. 
These  officials  regard  the  control  of  the  milk  supply  as  a  local  question 
to  be  worked  out  by  local  officers  and  dairymen. 


378  CITY  MILK  SUPPLY 

Municipal  Control  of  the  Milk  Supply. — Local  control  of  the  milk  sup- 
ply becomes  increasingly  difficult  as  a  city  grows.  A  village  or  small 
city  can,  if  it  will,  exercise  successful  supervision  over  the  dairies  that 
supply  it.  So  long  as  they  are  few  in  number  and  near  at  hand  the  health 
officer  can  keep  in  close  contact  with  the  producers  and  the  dairymen 
themselves  have  personal  interest  in  their  customers  but  when  the  pro- 
ducers become  so  many  that  they  are  in  a  sense  strangers  to  the  health 
office  and  their  trade  and  when  much  of  the  milk  comes  from  a  distance, 
control  becomes  general  instead  of  personal  and  loses  much  of  its  effective- 
ness. Some  cities  grow  to  such  size  that  close  inspection  of  the  dairies 
is  not  to  be  thought  of  because  of  its  prohibitive  expense.  Thus,  New 
York  City  in  1912  consumed  2,500,000  qt.  of  milk  daily.  It  was  pro- 
duced by  about  350,000  cows  on  44,000  farms  in  six  States  and  127,000 
people  were  estimated  to  be  engaged  in  the  daily  handling  of  the  milk. 
In  1915  over  80  per  cent,  of  the  milk  came  from  points  over  200  miles 
from  the  city  and  the  longest  haul  was  460  miles. 

Control  of  the  Milk  Supply  by  the  Contractor. — Reflection  on  such 
figures  as  these  suggests  inspection  of  dairies  by  the  contractor,  as  help- 
ful and  necessary.  The  law  usually  makes  a  dealer  in  foods  responsi- 
ble for  their  quality.  So,  as  a  business  proposition  it  is  good  policy  for  a 
milk  dealer  to  inspect  the  dairy  farms  that  supply  him.  Indeed,  some 
profess  to  believe  that  ultimately  the  dealer  will  assume  the  responsibility 
of  furnishing  adequate  inspection  and  that  official  inspection  will  become 
less  important.  However,  official  supervision  of  the  dealer's  inspection 
will  probably  always  be  necessary  because  in  most  dairy  districts  there  is 
competition  for  the  farmer's  milk  which  tends  to  make  the  dealer  adopt 
lenient  standards  of  inspection  in  order  to  hold  the  farmer's  business. 
Indeed,  some  authorities  are  inclined  to  believe  that  one  of  the  first  moves 
in  improving  the  quality  of  milk  furnished  any  community  should  be  to 
secure  an  abundant  supply  for,  so  long  as  there  is  only  enough  barely  to 
meet  the  needs  of  the  community,  the  dairyman  who  produces  inferior 
milk  can  market  it. 

So  then,  while  both  Federal  and  State  Governments  exercise  control 
over  the  milk  supply,  each  community  is  largely  dependent  on  its  own 
initiative  and  energy  for  securing  an  adequate  and  safe  supply  of  milk. 
A  milk  policy  must  be  adopted  and  this  policy  must  be  stated  in  the  form 
of  an  ordinance. 

Milk  Codes. — The  variety  in  milk  ordinances  is  almost  endless  but 
they  can  be  grouped  in  two  classes,  namely :  (1)  those  that,  though  they  con- 
form to  legal  usage,  are  verbose,  vague  in  meaning  and  provide  inadequate 
or  unworkable  standards;  and  (2)  those  that  are  concise,  easily  interpreted, 
in  accord  with  modern  standards  and  adapted  to  the  needs  of  the  commu- 
nity that  is  to  use  them.  The  cardinal  points  to  be  provided  for  are  that : 
(1)  An  officer  or  board  shall  be  designated  to  enforce  the  ordinance  and  be 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  379 

clothed  with  the  necessary  authority  and  provided  with  the  necessary 
funds  to  do  it.  (2)  Everyone  engaged  in  producing  or  vending  milk  shall 
be  required  to  take  out  a  permit  or  license  therefor  which  permit  shall  be 
non-transferable  and  revokable  by  the  officer  or  board,  if  the  provisions  of 
the  ordinance  are  not  complied  with .  (3)  There  shall  be  temperature  stand- 
ards governing  the  temperature  at  which  milk  shall  be  held  on  the  farm, 
in  transit  to  the  city,  in  storage  and  on  delivery  wagons  in  the  city.  (4) 
There  shall  be  chemical  standards  which  may  well  conform  to  those  estab- 
lished by  the  Federal  Government  or  by  the  State.  (5)  Bacteriological 
standards  may  be  established.  If  they  are,  care  should  be  taken  on  the 
one  hand  that  they  are  not  so  low  as  to  be  practically  impossible  to  attain 
and  on  the  other  that  they  are  not  so  high  as  to  be  farcical.  (6)  There 
should  be  standards  for  pasteurization.  These  should  specify  the  kinds 
of  pasteurization  that  are  allowable,  the  temperatures  and  period  of  heat- 
ing of  the  milk  and  should  require  the  use  of  automatic  recording  ther- 
mometers. Proper  labeling  of  pasteurized  milk  should  be  insisted  on 
which  means  that  the  date  of  pasteurization,  the  degree  of  temperature 
used  and  the  time  of  exposure  thereto  should  be  plainly  stated  on  the 
bottle.  Repasteurization  of  milk  for  sale  should  be  prohibited.  (7)  The 
policy  with  regard  to  the  control  of  bovine  tuberculosis  should  be  em- 
bodied in  the  ordinance.  (8)  The  sanitation  of  dairies,  country  and  city 
milk  plants  and  stores  where  milk  is  sold  should  be  covered.  Provision 
should  be  made  for  the  use  of  score  cards  and  the  sediment  test.  (9) 
For  the  protection  of  consumers  some  ordinances  establish  the  limit  of 
tolerance  for  milk  bottles  and  make  it  a  finable  offense  to  use  them  as 
containers  for  anything  but  milk.  In  a  few  cities  the  bottles  are  required 
to  be  marked  with  the  dealer's  name  and  dealers  are  prohibited  from  using 
one  another's  bottles. 

The  Grading  of  Milk. — Whether  a  system  of  grading  milk  shall  be 
provided  by  the  ordinance  must  receive  careful  consideration.  The  first 
step  toward  grading  was  a  resolution,  not  having  the  effect  of  law,  of  the 
New  York  Board  of  Health  advising  that  all  milk  for  drinking  should  be 
either  boiled  or  pasteurized  and  suggesting  that  milk  should  be  graded 
into  (1)  milk  for  babies  to  drink;  (2)  milk  for  adults  to  drink;  and  (3) 
milk  for  cooking  only.  This  is  still  the  broad  basis  for  grading  milk. 
In  1911  the  Board  announced  that  after  Jan.  1,  1912,  all  except  specially 
high-grade  milk  be  pasteurized  and  later  in  1911  as  a  result  of  a  joint  con- 
ference with  milk  dealers,  the  New  York  Milk  Committee  and  certain 
physicians  established  the  following  grades  for  milk: 

1912 
Grade  A. 

1.  Certified  or  guaranteed. 

2.  Inspected  raw. 

Dairies  must  attain  a  score  of  25  on  equipment  and  50  on  methods. 


380  CITY  MILK  SUPPLY 

The  bacterial  count  of  the  milk  must  not  exceed  60,000  per  cubic  centi- 
meter before  pasteurization  nor  50,000  when  delivered  to  consumer. 

Grade  B. 

1.  Selected  raw. 

Dairies  must  score  25  on  equipment  and  43  for  methods. 
The  bacterial  count  shall  not  be  excessive. 

2.  Pasteurized. 

No  requirements  either  as  to  dairy  score  or  bacterial  counts. 

Grade  C. 

For  cooking  only. 

At  first  it  was  permissible  to  sell  such  milk  in  a  raw  state  but  later  it  was 
made  requisite  to  pasteurize  it;  however,  no  standards  were  set  for  it. 
In  1913  as  the  result  of  a  milk-borne  typhoid-fever  epidemic,  grade  B  raw  milk 
was  abolished  and  bacterial  standards  for  all  the  grades  of  milk  were  established. 
Grade  A  was  simplified  and  the  pasteurization  of  cream  and  all  milk,  except 
Grade  A,  was  required.     The  grading  in  use  in  1915  was  the  following: 

1915 
Grade  A. 

1.  Raw.     The  cows  must  pass  the  tuberculin  test. 

Dairies  must  attain  a  score  of  25  on  equipment  and  50  on  method. 
The  bacterial  count  of  the  milk  must  not  exceed  60,000  per  cubic  centi- 
meter when  delivered  to  consumers. 

2.  Pasteurized. 

Dairies  must  attain  a  score  of  25  for  equipment  and  43  for  methods. 

The  bacterial  count  of  the  milk  must  not  exceed  200,000  per  cubic  centi- 
meter before  pasteurization  nor  30,000  per  cubic  centimeter  when  delivered 
to  the  consumer. 

Grade  B. 

Dairies  must  attain  a  score  of  20  on  equipment  and  35  on  methods. 

The  bacterial  count  of  the  milk  if  pasteurized  in  the  country  must  not 
exceed  300,000  per  cubic  centimeter,  or  if  pasteurized  in  the  city  1,500,000 
per  cubic  centimeter  before  pasteurization  and  the  bacterial  count  of 
neither  one  must  not  exceed  100,000  per  cubic  centimeter  when  delivered 
to  the  consumer. 

Grade  C. 

Pasteurized. 

Dairies  must  attain  a  total  score  of  40  and  the  bacterial  count  after 
pasteurization  must  not  exceed  300,000  per  cubic  centimeter. 

Grade  A  milk  which  is  intended  for  children  requires  the  most  super- 
vision; the  necessary  distinction  as  to  that  grade  is  obtained  by  forbidding 
grade  A  plants  to  handle  milk  of  lower  grade. 

With  regard  to  grade  B  milk  it  should  be  said  that  few  of  the  dairies 
are  scored  at  the  present  time  and  that  its  fitness  for  pasteurization  and 
use  is  determined  by  the  bacterial  count.  It  is  the  milk  that  is  used  by 
the  great  majority  of  the  people  of  New  York  City. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  381 

Objections  that  are  urged  to  establishing  a  system  of  grading  are  that: 
(1)  These  grades  which  are  practically  the  only  ones  in  use,  are  based  on 
insufficient  experimental  data  and  are  at  best  merely  tentative.  (2) 
There  should  be  but  one  grade  of  milk  and  that  should  be  of  sufficiently 
good  quality  to  pass  all  reasonable  tests  of  healthfulness.  (3)  The 
attempt  to  maintain  more  than  one  grade  of  milk  will  confuse  the  public 
and  impose  additional  costs  on  the  dealers  who  will  find  it  more  difficult 
to  conduct  a  profitable  business  working  under  a  system  of  grades  than 
under  a  single  standard  of  quality.  (4)  The  poor  will  be  the  purchasers 
of  the  inferior  milk.  (5)  The  public  is  not  educated  up  to  paying  for  the 
higher  grades  of  milk.  (6)  The  grading  of  milk  offers  opportunity  for  col- 
lusion between  the  dealer  and  the  Board  of  Health. 

In  favor  of  the  grading  system  it  is  urged :  (1)  All  food  products  except 
milk  are  sold  in  the  market  according  to  quality  or  grade  and  there  is  a 
clear  demand  by  the  public  for  three  grades  of  milk.  (2)  Milk  that  is 
handled  with  superior  care  should  not  be  forced  to  compete  with  ordinary 
milk.  (3)  While  there  has  been  a  notable  improvement  in  the  quality 
of  milk  sold  in  the  last  'decade  the  improvement  proceeds  too  slowly  for 
the  well-being  of  both  the  consumer  and  the  industry  and  it  can  best  be 
accelerated  by  the  establishment  of  grades.  (4)  The  contention  that  the 
poor  will  get  all  the  inferior  milk  is  without  merit  for  they  get  it  under  a 
non-graded  system.  The  tendency  of  grading  is  to  raise  the  average 
market  quality  which  is  a  benefit  in  which  the  poor  share.  (5)  There  is 
no  evidence  in  the  experience  of  New  York  dealers  that  the  grading  sys- 
tem reduced  profits.  (6)  While  it  is  true  fraudulent  practices  may  creep 
into  the  grading  system,  so  they  may  in  any  system  of  milk  control  and 
there  is  no  reason  to  suppose  that  the  honest  elements  of  society  will  be 
any  less  likely  to  be  successful  in  controlling  them  under  the  grading  sys- 
tem than  under  any  other. 

The  grading  system  has  attained  enough  success  in  New  York  to  make 
it  certain  that  in  the  future  some  system  of  grading  will  be  widely  used. 
The  experience  of  New  York  City  and  experiments  that  are  designed  to 
get  data  for  more  rational  grading  than  has  yet  been  possible  are  being 
watched  closely.  Till  more  information  is  available  the  grading  of  milk 
should  be  attempted  very  cautiously.  It  is  the  opinion  of  the  Committee 
on  Improvement  of  Milk  Supplies  of  the  International  Milk  Dealer's 
Association  that  the  discussion  of  the  establishment  of  the  purchase  of 
cream  on  a  basis  of  quality  for  the  manufacture  of  butter  in  the 
States  of  Iowa,  Missouri,  Kansas,  Nebraska,  Minnesota,  Wisconsin, 
Michigan,  Illinois  and  Ohio,  has  paved  the  way  for  the  advancement 
of  milk  grading. 

The  Milk  Code  Should  be  Suited  to  the  Community. — It  is  highly 
important  that  the  ordinance  shall  be  suited  to  the  community  which  is 
to  use  it.  The  mistake  is  often  made  of  copying  the  ordinance  of  a  city 


382  CITY  MILK  SUPPLY 

that  by  long  effort  has  improved  its  sources  of  supply,  its  milk  plants  and 
stores  where  milk  is  sold,  to  the  point  where  they  can  work  without  hard- 
ship under  a  rather  stringent  law,  in  a  city  that  is  just  beginning  a  cam- 
paign for  clean  milk  in  the  midst  of  crude  conditions.  The  result  is  that 
the  dairy  industry  is  financially  unable  to  meet  the  newly  imposed  regu- 
lations and  the  effort  to  improve  the  supply  comes  to  naught.  There  is 
the  same  result  when  the  attempt  is  made  to  thrust  the  ordinance  of  a 
big  city  on  a  small  one.  The  writer  once  heard  an  enthusiastic  physician 
advocate,  for  a  city  of  40,000  inhabitants,  an  ordinance  that  was  strikingly 
similar  to  that  of  New  York  City. 

It  ought  to  be  unnecessary  to  state  that  an  ordinance  is  stillborn 
unless  officers  are  appointed  and  money  appropriated  to  enforce  it  but 
those  who  are  secretly  hostile  to  ordinances  they  dare  not  openly  oppose 
often  nullify  them  by  neglecting  to  provide  these  very  things. 

Type  of  Ordinance  Proposed  by  Whitaker. — As  a  satisfactory  type 
of  city  milk  ordinance,  the  International  Association  of  Dairy  and  Milk 
Inspectors  has  endorsed  that  outlined  by  the  late  George  M.  Whitaker 
which  follows: 

"An  Act  (Ordinance)  to  Regulate  the  Sale  of  Milk  in 

» 

SECTION  1 
The  Requirement 

No  person,  himself,  or  by  his  servant  or  agent,  or  as  the  servant  or  agent  of 
another,  shall  sell  or  deliver  or  have  in  his  possession  or  custody  with  intent  to 
sell  or  deliver: 
>     1.  Milk  to  which  water  or  any  foreign  substance  has  been  added. 

2.  Milk  which  has  been  wholly  or  partially  skimmed. 

3.  Milk  not  of  standard  quality. 

4.  Milk  concerning  which  any  misrepresentation  has  been  made. 

5.  Milk  produced  by  diseased  cows  or  by  cows  that  have  been  fed  unwhole- 
some food  or  contaminated  water,  or 

6.  Milk  that  has  been  produced,  stored,  handled  or  transported  in  an  improper, 
unclean  or  insanitary  manner. 

SECTION  2 
Definitions  and  Exceptions 

For  the  purpose  of  this  Act  the  word  "person"  shall  be  construed  to  mean 
individual,  partnership  or  corporation;  the  word  "milk"  shall  mean  milk,  cream, 
or  evaporated  or  condensed  milk,  so  far  as  may  be  applicable;  the  expression 
"milk  not  of  standard  quality"  shall  mean  milk  having  less  than  8.5  per  cent. 
of|solids-not-fat  and  less  than  3.25  per  cent,  of  butterfat,  and  cream  having  less 
than  18  per  cent,  of  butterfat.  Skim-milk  having  less  than  9.3  per  cent,  of  milk 
solids  exclusive  of  fat  shall  be  considered  adulterated. 

Nothing  in  this  Act  shall  be  construed  to  prohibit  the  sale  of  skim-milk  or 
of  understandard  milk  if  the  receptacle  containing  the  same  and  from  which  it  is 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  383 

sold  is  plainly  marked  with  the  word  "  skim-milk "  in  the  case  of  skim-milk  or 
with  the  percentage  of  butterfat  contained  therein  in  the  case  of  understandard 
milk  or  cream.  The  aforesaid  words  and  figures  shall  be  distinct  and  conspicu- 
ous; they  shall  be  permanently  attached  to  the  aforesaid  container  above  the 
center  of  the  same;  they  shall  be  of  uncondensed  gothic  style  and  their  length 
shall  be  at  least  one-tenth  of  the  height  of  the  container  on  which  they  are  placed ; 
when  glass  bottles  are  used  the  required  marks  shall  be  blown  into  the  side  of  the 
bottle  and  also  distinctly  printed  on  the  cap  or  cover  of  the  same. 

Nothing  in  this  (Act  or  Ordinance)  shall  be  construed  to  prevent  the  sale  of 
modified  milk  in  bottles,  each  holding  a  single  feeding,  into  the  side  of  which  the 
name  of  the  person  who  manufactured  or  prepared  the  same  has  been  blown 
together  with  the  words  "Modified  Milk."  Nothing  in  this  (Act  or  Ordinance) 
shall  apply  to  evaporated  or  condensed  milk  contained  in  hermetically  sealed 
packages  labeled  distinctly  with  the  name  of  the  manufacturer  or  person  who 
prepared  or  put  it  up  and  the  brand  under  which  it  is  made  or  sold.  Certified 
milk  shall  mean  milk  produced  under  the  regulations  and  supervision  of  a  regular 
county  medical  society  acting  through  a  committee  or  commission  which  has 
certified  that  its  requirements  have  been  complied  with. 

For  the  purpose  of  this  Act,  cows  which  react  to  the  tuberculin  test  shall  be 
considered  diseased;  milk  produced  at  a  dairy  which  scores  (on  the  National 
Dairy  Division  "official"  score  card)  below  50  and  milk  sold  by  or  from  a  city 
milk  plant  which  scores  (on  the  National  Dairy  Division  "official"  score  card) 
below  70  shall  be  considered  as  produced  or  handled  in  an  improper,  unclean 
and  insanitary  manner.  Milk  from  a  cow  2  weeks  before  calving  and  5  days 
after,  shall  be  regarded  as  insanitary.  For  the  purpose  of  this  Act,  milk  with  a 
temperature  above  50°F.,  or  having  more  than  500,000  bacteria  per  cubic  centi- 
meter, shall  be  regarded  as  insanitary.  When  milk  is  bought  by  the  quart  or 
gallon,  the  gallon  of  231  cu.  in.  and  the  quart  of  57.75  cu.  in.  shall  be  standard 
and  shall  be  so  understood. 

SECTION  3 

Licenses 

Every  person  before  selling  milk  or  offering  it  for  sale,  or  before  conveying 
milk  in  carriages  or  otherwise  for  the  purpose  of  selling  or  delivering  it  in  the  city 

of shall  be  licensed  by  the  chief  of  the  Milk  Inspection  Bureau,  hereinafter 

provided  for,  to  sell  milk  within  the  limits  thereof,  and  shall  pay cents  to 

the  use  of  the  city.  The  license  fee  shall  be  paid  to  the  chief  of  the  Milk  Inspec- 
tion Bureau  and  by  him  turned  over  to  the  city  treasurer.  Licenses  shall  be 
issued  only  in  the  name  of  the  owners  of  carriages  or  other  vehicles,  or  stores  or 
booths.  They  shall  for  the  purpose  of  the  act  be  conclusive  evidence  of  owner- 
ship of  the  business,  and  shall  contain  a  serial  number  and  the  name,  residence 
and  place  of  business  of  the  licensee.  Each  licensee  before  engaging  in  the  sale 
of  milk  shall  cause  his  name  and  number  of  his  license  to  be  conspicuously  posted 
in  his  place  of  business  and  shall  cause  his  name,  the  number  of  his  license,  and 
his  place  of  business,  to  be  legibly  placed  on  each  side  of  all  carriages  or  vehicles 
used  by  him  in  the  conveyance  and  sale  of  milk.  The  application  shall  give  the 
name  of  all  drivers  and  other  persons  employed  by  the  applicant  in  conveying 
or  selling  milk.  It  shall  also  give  the  names  of  all  persons  from  whom  the  appli- 


384  CITY  MILK  SUPPLY 

cant  is  at  the  time  purchasing  or  receiving  milk,  their  residence  and  post-office 
address,  and  such  detailed  information  as  to  the  condition  of  their  cows  and  prem- 
ises and  their  methods  as  the  aforesaid  Chief  may  require.  The  application 
shall  contain  an  agreement  that  the  Chief  of  the  Milk  Inspection  Bureau,  his 
deputies  and  assistants  shall  have  the  right  to  inspect  the  cows,  premises  and 
methods  of  said  producer. 

Holders  of  licenses  shall  promptly  notify  in  writing  the  chief  of  the  Milk 
Inspection  Bureau  of  any  change  of  drivers  or  other  employees  or  of  any  change 
in  the  source  of  their  milk  supply.  Each  license  shall  be  granted  on  the  condition 
that  it  is  subject  to  suspension  for  violation  of  any  provision  of  this  (Act  or  Ordi- 
nance) or  of  any  regulation  thereunder.  All  licenses  shall  be  renewed  on  or  before 
the  first  day  —  —  of  each  year. 

SECTION  4 

Bureau  of  Milk  Inspection 

A  milk  inspection  Bureau  of  the  Health  Department  is  hereby  created.  The 
(Board  of  Health  or  Health  Commission)  shall  (annually  or  biennially)  appoint  a 
Chief  of  the  Milk  Inspection  Bureau  at  a  salary  of  $ —  — .  (Make  provision 
for  assistants,  chemist,  bacteriologist,  etc.,  if  place  is  large  enough.) 

The  aforesaid  Chief  shall  enforce  the  provisions  of  this  (Act  or  Ordinance) 
and  regulations  thereunder,  under  the  general  direction  of  Board  of  Health  (or 
Health  Commission)  and  be  responsible  to  (it  or  him)  for  the  conduct  of  his 
office.  The  chief  of  the  Milk  Inspection  Bureau  by  himself  or  a  duly  authorized 
deputy  or  assistant  shall  at  least  four  times  each  year  inspect  all  animals,  stables, 
milk  rooms,  vehicles,  places  of  business,  shipping  stations  and  other  buildings  or 
places  used  in  the  production,  handling,  transportation  or  storage  of  milk  for 
sale  in  the  city  of  which  he  is  officer,  using  the  score  card  of  the  Dairy  Division 
of  the  Bureau  of  Animal  Industry  of  the  United  States  Department  of  Agriculture 
(the  "official"  score  card),  and  rating  the  dairies  thereon.  He  shall  also  investi- 
gate the  health  of  employees  and  attendants  handling  the  milk  supply.  He 
shall  take  samples  of  milk  for  chemical  and  bacteriological  examination.  For  the 
purpose  of  enforcing  this  law  the  aforesaid  Chief  and  assistants  may  enter  all 
aforesaid  places  and  buildings  used  in  the  production  and  handling  of  milk  for  the 
city  of  which  he  is  an  officer;  he  shall  have  access  to  all  animals  producing  milk 
for  said  city  and  to  all  vessels  and  utensils  used  in  the  production,  preparation 
for  market,  and  sale  of  such  milk;  and  he  shall  be  allowed  to  take  samples  of 
milk  on  offering  payment  therefor.  He  may  revoke  or  suspend  the  licenses  here- 
tofore provided  for,  for  violation  of  this  law  or  of  the  regulations  made  thereunder. 
The  aforesaid  chief  of  the  Milk  Inspection  Bureau  shall  annually  test  or  cause 
to  be  tested  with  tuberculin,  all  cows  furnishing  milk  for  the  city  of  -  — . 

SECTION  5 
Miscellaneous 

A  person  suffering  from  any  contagious  disease,  or  one  in  whose  residence, 
or  among  whose  associates,  any  contagious  or  infectious  disease  exists,  must  keep 
away  from  cows,  milk  or  milk  utensils.  When  any  person  engaged  in  the  pro- 
duction, storage  or  distribution  of  milk  is  suffering  from  any  contagious  or  in- 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  385 

fectious  disease,  or  when  such  disease  exists  among  his  employees  or  their  im- 
mediate associates,  or  within  any  building  used  in  any  way  in  the  milk  business, 
no  milk  shall  be  sold  or  delivered  from  such  dairy  or  milk  establishment,  except 
by  permission  of  and  in  the  manner  prescribed  by  the  Board  of  Health.  No 
person  who  has  anything  to  do  in  the  production  or  handling  of  milk  shall  enter 
any  place  where  exists  any  contagious  or  infectious  disease  nor  have  any  communi- 
cation with  any  person  who  is  an  occupant  of  such  infected  places.  Every 
producer  who  sells  milk  directly  to  the  consumer  shall  promptly  notify  the  Board 
of  Health  of  any  case  of  communicable  disease  among  his  employees,  their  im- 
mediate associates,  or  members  of  his  family.  Every  milk  producer  who  sells  his 
product  to  a  middleman  for  resale  shall  notify  said  dealer  of  the  existence  of  any 
communicable  disease  as  aforesaid  and  said  dealer  shall  at  once  notify  the  Board 
of  Health. 

No  milk  shall  be  dipped  from  cans  or  poured  into  other  vessels  except  in  the 
regular  milk  room  of  a  dairy  plant.  No  milk  shall  be  bottled  upon  any  wagon. 

Milk  tickets  shall  be  used  but  once. 

No  one  shall  deliver  milk  to  or  remove  any  milk  bottle  or  receptacle  from  a 
dwelling  where  any  contagious  disease  exists,  until  authorized  by  the  Board  of 
Health  in  the  way  prescribed  by  the  Board. 

No  one  shall  place  or  permit  to  be  placed  in  any  vessel  or  utensil  used  in  the 
production,  sale  or  delivery  of  milk,  any  offal,  swill,  kerosene  oil  or  other  offensive 
material;  nor  shall  he  return  or  cause  to  be  returned  any  milk  can  or  bottle  which 
is  in  an  unclean  or  offensive  condition. 

The  presence  of  a  diseased  animal  in  a  herd  from  which  milk  is  sold  shall  be 
prima  facie  evidence  that  the  milk  of  the  diseased  animal  is  sold  contrary  to  law. 

The  Board  of  Health  (Health  Commission)  may  make  all  necessary  regula- 
tions for  enforcing  this  (Ordinance  or  Act). 

SECTION  6 
Penalties 

Whoever  violates  any  provision  of  this  Act  (Ordinance)  or  any  regulation 
made  under  its  authority,  and  whoever  hinders,  obstructs  or  interferes  with  the 
Chief  of  the  Milk  Inspection  Bureau  or  any  of  his  inspectors  or  assistants  in  the 

discharge  of  their  duty  shall  be  punished  by  a  fine  of  not  less  than  $ or  more 

than  $ ." 

Type  of  Ordinance  Proposed  by  the  New  York  Milk  Committee. — 
The  American  Public  Health  Association,  the  American  Medical  Associa- 
tion, the  Provincial  Boards  of  Health  of  North  America,  and  the  American 
Veterinary  Association  have  indorsed  the  Second  Report  of  the  Com- 
mission on  Milk  Standards  of  the  New  York  Milk  Committee.  The  re- 
port has  not  yet  been  indorsed  by  the  International  Association  of  Dairy 
and  Milk  Inspectors  whose  members  have  had  more  practical  experience 
in  the  regulation  of  milk  supplies  than  have  the  members  of  the  associa- 
tions that  have  approved  it.  Milk  ordinances  may  be  constructed  in 
accordance  with  the  principles  of  this  report,  which  follows. 

25 


386  CITY  MILK  SUPPLY 

NEED  OF  MILK  CONTROL 

Proper  milk  standards,  while  they  are  essential  to  efficient  milk  control  by 
public  health  authorities  and  have  as  their  object  the  protection  of  the  milk 
consumer,  are  also  necessary  for  the  ultimate  well-being  of  the  milk  industry 
itself.  Public  confidence  is  an  asset  of  the  highest  value  in  the  milk  business. 
The  milk  producer  is  interested  in  proper  standards  for  milk,  since  these  contrib- 
ute to  the  control  of  bovine  tuberculosis  and  other  cattle  diseases  and  distinguish 
between  the  good  producer  and  the  bad  producer.  The  milk  dealer  is  immedi- 
ately classified  by  milk  standards,  either  into  a  seller  of  first-class  milk  or  a  seller 
of  second-class  milk,  and  such  distinction  gives  to  the  seller  of  first-class  milk 
the  commercial  rewards  which  he  deserves,  while  it  inflicts  just  penalties  on  the 
seller  of  second-class  milk.  For  milk  consumers,  the  setting  of  definite  standards 
accompanied  by  proper  labeling  makes  it  possible  to  know  the  character  of  the 
milk  which  is  purchased  and  to  distinguish  good  milk  from  bad  milk.  In  the 
matter  of  public  health  administration,  standards  are  absolutely  necessary  to 
furnish  definitions  around  which  the  rules  and  regulations  of  city  health  depart- 
ments can  be  drawn,  and  the  milk  supply  efficiently  controlled. 

PUBLIC  HEALTH  AUTHORITIES 

While  public  health  authorities  must  necessarily  see  that  the  source  of  supply 
and  the  chemical  composition  should  correspond  with  established  definitions  of 
milk  as  a  food,  their  most  important  duty  is  to  prevent  the  transmission  of  dis- 
ease through  milk.  This  means  the  control  of  infantile  diarrhea,  typhoid  fever, 
tuberculosis,  diphtheria,  scarlet  fever,  septic  throat  infections,  and  other  infec- 
tious diseases  in  so  far  as  they  are  carried  by  milk. 

SEPTIC  SORE  THROAT 

Septic  sore  throat  deserves  special  mention  because  of  the  frequency  in  recent 
years  with  which  outbreaks  of  this  disease  have  been  traced  to  milk  supplies. 
The  suggestion  has  been  made  that  the  infection  of  the  milk  is  due  to  udder  in- 
fection of  the  cow  and  on  the  other  hand  it  has  been  suggested  that  it  is  due  to 
contact  with  infected  persons.  The  uncertainty  cannot  be  dispelled  until  cases 
of  septic  sore  throat  are  regularly  reported  and  tabulated  by  public  health 
authorities.  The  commission,  therefore,  recommends  that  public  health  authori- 
ties make  septic  sore  throat  a  reportable  disease. 

ECONOMIC  PROBLEM 

The  commission  recognizes  the  magnitude  of  the  milk  industry,  and  that  the 
improvement  of  milk  supplies  is  primarily  an  economic  problem.  The  success 
achieved  by  the  experiment  in  milk  production,  which  has  been  carried  out  on  a 
very  large  scale  by  the  New  York  Dairy  Demonstration  Co.,  is  an  illustration  of 
the  fact  that  an  extra  price  or  premium  paid  to  the  producer  for  cleanliness  and 
care  will  bring  results  far  more  quickly  and  certainly  than  instructions  or  official 
inspection.  But  while  the  basic  problem  is  economic,  and  must  eventually  be 
solved  by  commerce,  public  health  authorities  must  show  the  way  and  must 
establish  standards  and  regulations  in  the  interest  of  consumers,  the  value  t)f 
which  even  the  consumers  themselves  often  fail  to  appreciate.  >  •• 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  387 

A  prime  requisite  of  effectiveness  is  that  local  milk  laws  shall  not  exceed 
sanitary  limitations.  The  commission  has  not  entered  into  a  discussion  of  funda- 
mental State  laws,  but  it  recommends  that  State  laws  be  amended  wherever 
necessary  in  order  that  every  municipality  may  have  the  legal  right  to  adopt 
whatever  ordinances  it  sees  fit  for  the  improvement  of  the  milk  supply.  The 
commission  advocates  that  local  health  laws  be  carefully  drawn  with  regard  to 
their  legality  under  the  general  laws  of  the  localities  to  which  they  apply,  since- 
a  decision  against  a  milk  law  in  one  locality  is  liable  to  be  used  as  a  precedent 
against  milk  laws  elsewhere. 

STANDARD  RULES  AND  REGULATIONS 

The  commission  has  drawn  up  a  set  of  standard  rules  and  regulations  for  the 
control  of  milk.  These  are  the  result  of  a  study  of  the  printed  rules  and  regula- 
tions of  the  cities  of  the  United  States  and  of  foreign  countries  and  represent  an 
immense  amount  of  work  on  the  part  of  the  special  committee  of  the  commission 
to  which  the  task  was  assigned.  Some  communities  are  in  a  position  to  adopt  all 
of  these  rules  and  regulations  at  the  present  time,  while  other  communities  will 
be  obliged  to  adopt  a  few  rules  at  a  time  as  public  sentiment  and  local  conditions 
warrant.  It  is  realized  that  some  of  the  rules  may  have  to  be  modified  to  meet 
local  conditions.  It  seems  wise  to  the  commission  to  divide  the  regulations  into 
two  parts:  First,  requirements,  under  which  head  are  set  down  those  provisions 
which  are  so  fundamentally  necessary  that  no  community  is  justified  in  compro- 
mising on  them;  second,  recommendations,  under  which  head  are  set  down  pro- 
visions which  are  necessary  for  a  good  milk  supply,  but  on  which  there  can  be  a 
certain  amount  of  latitude  for  compromise  by  those  communities  in  which  public 
sentiment  is  not  ready  to  support  more  than  a  moderate  degree  of  protection  of 
human  life. 

ADMINISTRATIVE  EQUIPMENT 

Another  prime  requisite  is  that  the  administrative  departments  shall  be  ade- 
quately equipped  with  men,  money,  and  laboratory  facilities.  In  smaller  com- 
munities cooperation  between  local  boards  of  health  to  the  extent  of  exchanging 
reports  would  eliminate  much  duplication.  Where  a  community  cannot  maintain 
a  laboratory  it  can  enter  into  laboratory  arrangements  with  other  communities, 
and  several  can  combine  in  the  use  of  a  common  laboratory.  Much  of  the  ex- 
pense of  tuberculin  testing  can  be  borne  by  the  National  and  State  Governments. 
The  commission  is  of  the  opinion  that  results  cannot  be  expected  from  laws  where 
there  is  not  sufficient  appropriation  and  where  there  is  no  machinery  for  their 
enforcement.  On  this  subject  the  commission  passed  a  resolution  as  follows: 

Whereas  the  appropriations  generally  made  for  the  purposes  of  carrying  on  labora- 
tory analyses  of  milk  are  now  in  most  cases  entirely  inadequate :  Therefore  be  it 

Resolved,  That  this  commission  recommends  for  the  consideration  of  the  authorities 
concerned  an  appropriation  of  funds  commensurate  with  the  importance  of  laboratory 
methods,  which  are  of  paramount  importance  in  the  hygienic  control  of  the  milk 
supply. 

GRADING  OF  MILK 

There  is  no  escape  from  the  conclusion  that  milk  must  be  graded  and  sold  on 
grade,  just  as  wheat,  corn,  cotton,  beef,  and  other  products  are  graded.  The 


388  CITY  MILK  SUPPLY 

milk  merchant  must  judge  of  the  food  value  and  also  of  the  sanitary  character 
of  the  commodity  in  which  he  deals.  The  high-grade  product  must  get  a  better 
price  than  at  present.  The  low-grade  product  must  bring  less.  In  separating 
milk  into  grades  and  classes  the  commission  has  endeavored  to  make  its  classi- 
fication as  simple  as  possible  and  at  the  same  time  to  distinguish  between  milks 
which  are  essentially  different  in  sanitary  character. 

In  general  two  great  classes  of  milk  are  recognized,  namely,  raw  milk  and 
pasteurized  milk.  Under  these  general  classes  there  are  different  grades,  as  indi- 
cated in  the  report  of  the  committee  on  classification. 

PASTEURIZATION 

While  the  process  of  pasteurization  is  a  matter  which  has  attracted  a  great 
deal  of  attention  in  recent  years,  the  commission  has  not  entered  into  any  discus- 
sion of  its  merits  or  demerits,  but  has  given  it  recognition  in  its  classification  as 
a  process  necessary  for  the  treatment  of  milk  which  is  not  otherwise  protected 
against  infection. 

The  commission  thinks  that  pasteurization  is  necessary  for  all  milk  at  all 
times,  excepting  grade  A,  raw  milk.  The  majority  of  the  commissioners  voted 
in  favor  of  the  pasteurization  of  all  milk,  including  grade  A,  raw  milk.  Since 
this  was  not  unanimous  the  commission  recommends  that  the  pasteurization  of 
grade  A,  raw  milk,  be  optional. 

The  process  of  pasteurization  should  be  under  official  supervision.  The  super- 
vision should  consist  of  a  personal  inspection  by  the  milk  inspector;  the  inspec- 
tions shall  be  as  frequent  as  possible.  Automatic  temperature  regulators  and 
recording  thermometers  should  be  required  and  the  efficiency  of  the  process  fre- 
quently determined  by  laboratory  testing. 

The  destruction  of  the  chemical  constituents  of  milk  by  heat  occurs  at  higher 
temperatures  than  those  necessary  for  the  destruction  of  the  bacteria  of  infectious 
diseases  transmissible  by  milk.  (See  Fig.  41,  p.  279.) 

The  commission  passed  a  resolution  regarding  the  temperature  of  pasteuriza- 
tion as  follows: 

That  pasteurization  of  milk  should  be  between  the  limits  of  140°F.  and  155°F. 
At  HOT.  the  minimum  exposure  should  be  20  min.  For  every  degree  above 
140°F.  the  time  may  be  reduced  by  1  min.  In  no  case  should  the  exposure  be  for 
less  than  5  min. 

In  order  to  allow  a  margin  of  safety  under  commercial  conditions  the  com- 
mission recommends  that  the  minimum  temperature  during  the  period  of  holding 
should  be  made  145°F.  and  the  holding  time  30  min.  Pasteurization  in  bulk 
when  properly  carried  out  has  proven  satisfactory,  but  pasteurization  in  the  final 
container  is  preferable. 

It  is  the  sense  of  the  commission  that  pasteurization  in  the  final  container 
should  be  encouraged. 

LABELING  AND  DATING  OF  MILK 

The  commission  voted  that  all  milk  should  be  labeled  and  marked  with  the 
grade  in  which  it  is  to  be  sold.  In  dating  milk  uniform  methods  should  be 
adopted  for  all  grades  of  both  raw  milk  and  pasteurized  milk,  both  using  the  day 
of  the  week  or  both  using  the  day  of  the  month.  All  milk  should  be  dated  uni- 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  389 

formly  with  the  date  of  delivery  to  the  consumer.  Raw  milk  should  not  be  dated 
with  the  date  of  production  while  pasteurized  milk  is  dated  with  the  date  of 
pasteurization,  since  this  places  certified  milk  at  a  disadvantage  by  making  it 
possible  for  pasteurized  milk  of  a  lower  grade  to  carry  a  later  date.  The  stamp- 
ing on  the  label  of  the  day  of  the  week  is  sufficient  for  dating. 

BACTERIA 

The  subject  of  bacteria  in  milk  received  more  attention  than  any  other  matter 
brought  before  the  commission.  The  commission  recognizes  that  bacteria  in 
milk  in  the  majority  of  instances  indicate  dirt,  or  lack  of  refrigeration,  or  age, 
while  in  the  minority  of  instances  the  bacteria  of  disease  may  be  present.  The 
routine  laboratory  methods  for  examining  milk  have  as  their  purpose  only  the 
control  over  dirt,  refrigeration,  and  age,  and  it  is  a  rare  thing  for  a  laboratory  to 
undertake  the  examination  of  milk  for  the  bacteria  of  disease  because  of  the  ex- 
treme difficulties  in  detecting  them.  The  more  efficacious  method  of  protecting 
milk  from  infection  by  the  bacteria  of  human  contagion  is  by  medical,  veterinary, 
and  sanitary  inspection,  and  by  pasteurization.  Milk  with  a  high  bacteria  count 
is  not  necessarily  harmful,  but  when  used  as  a  food,  particularly  for  children,  is 
a  hazard  too  great  to  be  .warranted.  Milk  with  a  high  bacteria  count,  therefore, 
should  be  condemned.  Milks  with  small  numbers  of  bacteria  are  presumed  to 
be  wholesome,  unless  there  is  reasonable  ground  for  suspecting  that  they  have 
been  exposed  to  contagion. 

BACTERIAL  STANDARDS 

The  commission  recognizes  the  difficulty  in  interpreting  bacteria  counts.  At 
times  misleading  conclusions  have  been  drawn  from  such  counts.  In  establishing 
the  bacterial  standards  for  a  city  it  is  always  necessary  to  take  into  consideration  the 
necessary  age  of  the  milk  and  in  lesser  measure  the  distance  hauled  and  methods 
employed  in  its  hauling.  It  will  always  be  possible  for  a  community  which 
consumes  milk  produced  on  its  own  premises,  or  within  12  hr.  of  its  production, 
to  insist  upon  and  maintain  a  lower  bacterial  standard  than  can  one  where  the 
milk  is  hauled  many  miles  into  town  in  a  wagon,  to  be  consumed  within  24  hr. 
after  it  is  produced.  In  like  manner  this  second  type  of  city  can  always  maintain 
a  lower  bacterial  standard  than  a  city  where  the  general  milk  supply  is  hauled  by 
railroad  long  distances  and  is  several  days  old  when  consumed.  In  drawing  con- 
clusions as  to  the  relative  efficacy  of  milk  control  in  cities  comparisons  must  be 
made  between  cities  of  the  same  class. 

The  commission  deems  it  of  the  utmost  importance  that  some  standard 
method  should  be  adopted  for  estimating  and  comparing  the  bacterial  character 
of  mliks,  since  by  this  means  only  is  it  possible  to  grade  and  classify  milks  and  to 
enforce  bacterial  standards.  There  is  much  diversity  of  opinion  as  to  the  best 
method  of  valuing  bacteria  counts.  The  average  of  a  series  gives  results  which 
are  misleading  about  as  frequently  as  otherwise.  In  the  average  a  single  high 
figure  may  unduly  overbalance  a  large  number  of  exceedingly  low  counts.  There 
are  objections  to  the  use  of  the  " median"  or  middle  number  when  the  counts  are 
arranged  in  order  of  size,  for  the  reason  that  the  middle  figure  does  not  distinguish 
between  two  groups  in  one  of  which  there  may  be  some  very  high  counts  above 
the  median  and  in  the  other  of  which  there  are  none.  The  method  of  dividing 


390  CITY  MILK  SUPPLY 

results  into  groups  as  recommended  by  the  American  Public  Health  Association, 
while  a  step  in  the  right  direction,  is  cumbersome  and  does  not  clearly  indicate 
whether  or  not  a  milk  conforms  to  a  given  bacterial  standard. 

The  commission  passed  a  resolution  at  its  last  meeting  regarding  the  number 
of  bacterial  tests  necessary  to  determine  the  grade  into  which  a  milk  falls,  as 
follows : 

That  the  grade  into  which  a  milk  falls  shall  be  determined  bacteriologically  by  at 
least  five  consecutive  bacteria  counts  taken  over  a  period  of  not  less  than  one  week  nor 
more  than  one  month,  and  at  least  80  per  cent,  (four  out  of  five)  must  fall  below  the 
limit  set  for  the  grade  for  which  the  classification  is  desired. 

On  the  subject  of  laboratory  examinations  of  milk  for  bacteria  the  commis- 
sion passed  the  following  resolutions : 

1.  That  the  interests  of  public  health  demand  that  the  control  of  milk  supplies, 
both  as  to  production  and  distribution,  shall  include  regular  laboratory  examinations 
of  milk  by  bacteriological  methods. 

2.  That  among  present  available  routine  laboratory  methods  for  determining  the 
sanitary  quality  of  milk  the  bacteria  count  occupies  first  place. 

3.  That  bacteriological  standards  should  be  a  factor  in  classifying  or  grading  milks 
of  different  degrees  of  excellence. 

4.  That  in  determining  the  grade  or  class  of  a  raw  milk  the  specimen  taken  for 
bacteriological  examination  should  be  of  milk  as  offered  for  sale. 

5.  That  there  should  be  bacteriological  standards  for  pasteurized  milk  which 
should  require  laboratory  examination  of  samples  immediately  before  pasteurization 
as  well  as  of  milk  offered  for  sale. 

6.  That  the  bacteria  count  of  milk  indicates  its  quality  and  history  as  it  is  modified 
by  contamination,  handling,  dirt,  temperature,  or  age.     A  high  count  indicates  the 
necessity  of  investigation  and  inspection. 

7.  That  there  be  adopted  as  standards  for  making  the  bacteria  count  the  standard 
methods  of  the  American  Public  Health  Association,  laboratory  section,  recommend- 
ing, however,  the  following  amendments : 

A.  That  the  culture  medium  used  for  testing  milk  be  identical  in  its  composition 
and  reaction  with  the  culture  medium  used  for  the  testing  of  water  provided  in  the 
standard  methods  of  water  analyses  of  the  American  Public  Health  Association. 

B.  That  incubation  of  plate  cultures  be  made  at  37°C.  for  48  hr. 

The  bacterial  standards  given  in  the  report  are  the  work  of  a  special  com- 
mittee of  bacteriologists  who  considered  all  of  the  bacterial  standards  now  in  use. 
It  is  believed  that  the  standards  suggested  are  fair  and  wise  and  give  full  considera- 
tion to  the  state  of  the  industry  and  of  public  health  control.  The  commission 
believes  that  the  adoption  and  enforcement  of  these  bacterial  standards  will  be 
more  effective  than  any  other  one  thing  in  improving  the  sanitary  character  of 
public  milk  supplies.  The  enforcement  of  these  standards  can  be  carried  out 
only  by  the  regular  and  frequent  laboratory  examinations  of  milks  for  the  num- 
bers of  bacteria  they  may  contain. 

CHEMICAL  STANDARDS 

The  chemical  standards  suggested  are  the  work  of  a  special  committee,  com- 
posed of  chemists,  which  has  carefully  considered  the  natural  composition  of 
milk  and  the  Federal  and  State  standards  already  established.  The  standard  of 
3.25  per  cent,  fat  and  8.5  per  cent,  solids,  not  fat,  here  proposed  is  in  accordance 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  391 

with  the  recommendations  of  the  Association  of  Official  Agricultural  Chemists 
and  has  been  adopted  by  the  United  States  Department  of  Agriculture  and  by  a 
larger  number  of  States  than  has  any  other  standard.  The  simplification  of  the 
Babcock  test  makes  the  determination  of  fats  and  solids-not-fat  an  easy  procedure 
quickly  applied.  Such  chemical  examinations  of  milk  can  be  readily  adopted 
and  executed  by  any  health-board  laboratory  at  a  very  moderate  expense.  It  is 
believed  that  such  chemical  standards  as  are  suggested  will  inflict  no  real  hard- 
ship on  the  milk  producers  of  this  country  and  that  the  provision  regarding  sub- 
standard milks  is  a  liberal  one. 

MICROSCOPIC  EXAMINATION  OF  MILK 

Because  of  studies  which  have  been  made  during  the  past  year  the  commission 
thinks  it  wise  to  omit  temporarily  any  definite  statement  on  the  subject  of  micro- 
scopical examination  of  milk,  and  the  determination  of  pus  and  bacteria  by  sedi- 
mentation methods,  until  further  studies  have  been  made.  A  special  subcom- 
mittee has  been  appointed  for  this  purpose  which  will  make  studies  during  the 
present  year  and  the  commission  will  take  action  on  this  matter  at  one  of  its  later 
meetings. 

MlSLABELING 

The  commission  resolved  that  the  sale  of  milk  which  is  mislabeled  or  mis- 
branded  shall  be  punished  by  suitable  penalties. 

PUBLICITY 

H 

The  commission  fully  considered  the  matter  of  the  publication  of  laboratory 
examinations  of  milk  by  city  and  town  health  authorities.  When  proper  stand- 
ards and  regulations  are  established  and  adequate  facilities  furnished  for  labora- 
tory work,  it  is  believed  that  the  laboratory  tests  will  give  an  index  of  the  charac- 
ter of  the  milk  delivered  to  the  public  by  milk  sellers  which  is  entirely  fair  and 
impartial.  There  can  be  no  objection  to  publicity  under  such  circumstances. 
It  is  an  advantage  to  the  seller  of  high-grade  milk.  It  is  an  advantage  to  the 
consumer  who  desires  to  select  a  high-grade  milk.  It  has  much  educational 
value  both  to  producer  and  consumer.  Therefore  the  commission  recommends 
"that  the  reports  of  laboratory  analyses  of  milk  made  by  departments  of  health 
be  regularly  published." 

MEDICAL  INSPECTION 

It  is  the  sense  of  the  commission  that  the  medical  inspection  of  dairy  em- 
ployees should  be  emphasized  in  all  ways  possible. 

MILK  DEALER'S  LICENSE 

The  commission  resolved  that  a  dealer  shall  be  required  to  have  a  permit  or 
license  to  sell  any  grade  or  class  of  milk  and  to  use  a  label  for  such  class  or  grade. 
Such  permit  or  license  shall  be  revoked  and  the  .use  of  the  label  forbidden  when 
the  local  health  authorities  shall  determine  that  the  milk  is  not  in  the  class  or 
grade  designated. 


392  CITY  MILK  SUPPLY 

DESIGNATION  OF  GRADE 

The  commission  resolved  that  the  grade  of  milk  shall  be  designated  by  letter. 
It  is  the  sense  of  the  commission  that  the  essential  part  is  the  lettering  and  that 
all  other  words  on  the  label  are  explanatory. 

In  addition  to  the  letters  of  the  alphabet,  used  on  caps  or  labels,  the  use  of 
other  terms  may  be  permitted  so  long  as  such  terms  .are  not  the  cause. of  deception. 

Caps  and  labels  shall  state  whether  milk  is  raw  or  pasteurized.  The  letter 
designating  the  grade  to  which  milk  belongs  shall  be  conspicuously  displayed  on 
the  caps  of  bottles  or  the  labels  on  cans. 

CLASSIFICATION  OF  MILK 

It  was  resolved  that  the  classification  of  milk  contained  in  the  first  report 
of  the  commission  be  amended  as  follows : 

Milk  shall  be  divided  into  three  grades,  which  shall  be  the  same  for  both 
large  and  small  cities  and  towns,  and  which  shall  be  designated  by  the  first  three 
letters  of  the  alphabet.  The  requirements  shall  be  as  follows: 

GRADE   A 

Raw  milk. — Milk  of  this  class  shall  come  from  cows  free  from  disease  as  determined 
by  tuberculin  tests  and  physical  examinations  by  a  qualified  veterinarian,  and  shall 
be  produced  and  handled  by  employees  free  from  disease  as  determined  by  medical 
inspection  of  a  qualified  physician,  under  sanitary  conditions  such  that  the  bacteria 
count  shall  not  exceed  100,000  per  cubic  centimeter  at  the  time  of  delivery  to  the 
consumer.  It  is  recommended  that  dairies  from  which  this  supply  is  obtained  shall 
score  at  least  80  on  the  United  States  Bureau  of  Animal  Industry  score  card. 

Pasteurized  milk. — Milk  of  this  class  shall  come  from  cows  free  from  disease  as 
determined  by  physical  examinations  by  a  qualified  veterinarian  and  shall  be  pro- 
duced and  handled  under  sanitary  conditions  such  that  the  bacteria  count  at  no  time 
exceeds  200,000  per  cubic  centimeter.  All  milk  of  this  class  shall  be  pasteurized 
under  official  supervision,  and  the  bacteria  count  shall  not  exceed  10,000  per  cubic 
centimeter  at  the  time  of  delivery  to  the  consumer.  It  is  recommended  that  dairies 
from  which  this  supply  is  obtained  should  score  65  on  the  United  States  Bureau  of 
Animal  Industry  score  card. 

The  above  represents  only  the  minimum  standards  under  which  milk  may  be 
classified  in  grade  A.  The  commission  recognizes,  however,  that  there  are  grades 
of  milk  which  are  produced  under  unusually  good  conditions,  in  especially  sani- 
tary dairies,  many  of  which  are  operated  under  the  supervision  of  medical  asso- 
ciations. Such  milks  clearly  stand  at  the  head  of  this  grade. 

GRADE  B 

Milk  of  this  class  shall  come  from  cows  free  from  disease  as  determined  by  physical 
examinations,  of  which  one  each  year  shall  be  by  a  qualified  veterinarian,  and  shall 
be  produced  and  handled  under  sanitary  conditions  such  that  the  bacteria  count  at  no 
time  exceeds  1,000,000  per  cubic  centimeter.  All  milk  of  this  class  shall  be  pasteur- 
ized under  official  supervision,  and  the  bacteria  count  shall  not  exceed  50,000*per 
cubic  centimeter  when  delivered  to  the  consumer. 

It  is  recommended  that  dairies  producing  grade  B  milk  should  be  scored  and  that 
the  health  departments  or  the  controlling  departments,  whatever  they  may  be, 
strive  to  bring  these  scores  up  as  rapidly  as  possible. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  393 

GRADE   C 

Milk  of  this  class  shall  come  from  cows  free  from  disease  as  determined  by  physical 
examinations  and  shall  include  all  milk  that  is  produced  under  conditions  such  that 
the  bacteria  count  is  in  excess  of  1,000,000  per  cubic  centimeter. 

All  milk  of  this  class  shall  be  pasteurized,  or.  heated  to  a  higher  temperature,  and 
shall  contain  less  than  50,000  bacteria  per  cubic  centimeter  when  delivered  to  the 
customer.  It  is  recommended  that  this  milk  is  used  for  cooking  or  manufacturing 
purposes  only. 

Whenever  any  large  city  or  community  finds  it  necessary,  on  account  of  the  length 
of  haul  or  other  peculiar  conditions,  to  allow  the  sale  of  grade  C  milk,  its  sale  shall  be 
surrounded  by  safeguards  such  as  to  insure  the  restriction  of  its  use  to  cooking  and 
manufacturing  purposes. 

CLASSIFICATION  OF  CREAM 

Cream  should  be  classified  in  the  same  grades  as  milk,  in  accoradnce  with 
the  requirements  for  the  grades  of  milk,  excepting  the  bacterial  standards  which 
in  20  per  cent,  cream  shall  not  exceed  five  times  the  bacterial  standard  allowed 
in  the  grade  of  milk. 

Cream  containing  other  percentages  of  fat  shall  be  allowed  a  modification  of 
this  required  bacterial  standard  in  proportion  to  the  change  in  fat. 

CHFMICAL  STANDARDS 

Cow's  Milk. — Standard  milk  should  contain  not  less  than  8.5  per  cent,  of 
milk  solids-not-fat  and  not  less  than  3.25  per  cent,  of  milk  fat. 

Skim  Milk. — Standard  skim  milk  should  contain  not  less  than  8.75  per  cent, 
of  milk  solids. 

"  Cream. — Standard  cream  contains  not  less  than  18  per  cent,  of  milk  fat  and 
is  free  from  all  constituents  foreign  to  normal  milk.  The  percentage  of  milk  fat 
in  cream  over  or  under  that  standard  should  be  stated  on  the  label. 

Buttermilk. — Buttermilk  is  the  product  that  remains  when  fat  is  removed  from 
milk  or  cream,  sweet  or  sour,  in  the  process  of, churning.  Standard  buttermilk 
contains  not  less  than  8.5  per  cent,  of  milk  solids.  When  milk  is  skimmed,  soured, 
or  treated  so  as  to  resemble  buttermilk,  it  should  be  known  by  some  distinctive 
name. 

HOMOGENIZED  MILK  OR  CREAM 

The  commission  is  of  the  opinion  that  in  the  compounding  of  milk  no  fats 
other  than  milk  fats  from  the  milk  in  process  should  be  used  and  that  no  sub- 
stance foreign  to  milk  should  be  added  to  it.  The  commission  is  opposed  to  the 
use  of  condensed  milk  or  other  materials  for  the  thickening  of  cream  unless  the 
facts  are  clearly  set  forth  on  the  label  of  the  retail  package.  Regarding  the  proc- 
ess of  homogenizing,  the  commission  resolved  as  follows : 

That  homogenized  milk  or  cream  should  be  so  marked,  stating  the  percentage  of  fat 
that  it  contains. 

ADJUSTED  MILKS 

On  the  question  of  milks  and  creams  in  which  the  ratio  of  the  fats  to  the 
solids-not-fat  has  been  changed  by  the  addition  to  or  subtraction  of  cream  or 
milk  fat  the  commission  has  hesitated  to  take  a  position.  On  the  one  hand  they 


394  CITY  MILK  SUPPLY 

are  in  favor  of  every  procedure  which  will  increase  the  market  for  good  milk  and 
make  the  most  profitable  use  of  every  portion  of  it.  On  the  other,  they  recognize 
the  sensitiveness  of  milk,  the  ease  with  which  it  is  contaminated,  and  the  diffi- 
culty of  controlling,  standardizing,  skimming,  homogenizing,  souring,  etc.,  so 
that  contaminations  do  not  occur  and  inferior  materials  are  not  used.  On  this 
subject  the  commission  passed  a  resolution  presented  by  a  special  committee  as 
follows: 

Milk  in  which  the  ratio  of  the  fats  to  the  solids-not-fat  has  been  changed  by  the 
addition  to  or  subtraction  of  cream  should  be  labeled  "adjusted  milk;"  the  label 
should  show  the  minimum  guaranteed  percentage  of  fat  and  should  comply  with  the 
same  sanitary  or  chemical  requirements  as  for  milk  not  so  standardized  or  modified. 

REGULATION  OF  MARKET  MILK  ON  BASIS  OF  GUARANTEED  PERCENTAGE 

COMPOSITION 

1.  Sellers  of  milk  should  be  permitted  choice  of  one  of  two  systems  in  handling 
market  milk.     Milk  can  be  sold,  first,  under  the  regular  standard,  or,  second, 
under  a  guaranteed  statement  of  composition. 

2.  Any  normal  milk  may  be  sold  if  its  per  cent,  of  fat  is  stated.     In  case  the 
per  cent,  of  fat  is  not  stated,  the  sale  will  be  regarded  as  a  violation  unless  the 
milk  contains  at  least  3.25  per  cent,  of  milk  fat. 

3.  As  a  further  protection  to  consumers,  it  is  desirable  that  when  the  guaranty 
system  is  used  there  be  also  a  minimum  guaranty  of  milk  solids-not-fat  of  not 
less  than  8.5  per  cent. 

4.  Dealers  electing  to  sell  milk  under  the  guaranty  system  should  be  required 
to  state  conspicuously  the  guaranty  on  all  containers  in  which  such  milk  is 
handled  by  the  dealer  or  delivered  to  the  consumer. 

5.  The  sale  of  milk  on  a  guaranty  system  should  be  by  special  permission 
obtained  from  some  proper  local  authority. 

PENALTY 

Every  milk  ordinance  should  contain  a  penalty  clause. 

EXTENSION  WORK 

The  commission  indorsed  the  efforts  of  the  New  York  Milk  Committee  to 
obtain  funds  for  the  formation  of  a  bureau  of  extension  work,  such  bureau  to  act 
aS  ai  collecting  station  for  information  regarding  standards  and  regulations  as  to 
milk  adopted  by  cities  and  towns  in  the  United  States.  The  bureau  should  also 
furnish  information  to  such  cities  and  towns  as  appeal  for  aid  in  the  adoption  of 
milk  standards  and  should  conduct  a  constructive  program  by  placing  in  the 
field  a  man  who  would  visit  communities  interested  in  establishing  milk  standards; 
and  it  may  use  the  members  of  the  commission  on  milk  standards  for  carrying 
on  the  work  of  the  bureau  so  far  as  possible  in  their  own  localities. 


APPENDIX 

STANDARD  RULES  FOR  THE  PRODUCTION,  HANDLING,  AND  DISTRIBUTION  OF  MILK 

As  a  basis  for  the  promulgation  of  rules  and  recommendations  governing  the 
production,  handling,  and  distribution  of  milk,  it  is  recognized  that  we  have  to 
deal  with  two  kinds  of  milk,  raw  and  pasteurized,  although  there  may  be  several 
grades  of  each  of  these  two  kinds.  In  order  for  any  grade  to  be  safe,  it  is  recom- 
mended that  the  regulations  herein  set  forth  under  the  heading  "Requirements" 
should  be  enforced.  The  regulations  herein  set  forth  under  the  heading  "  Rec- 
ommendations" should  be  adopted  wherever  practicable  as  a  means  of  improving 
the  milk  supply  above  the  actual  point  of  safety.  (The  term  "milk"  shall  be 
construed  to  include  the  fluid  derivatives  of  milk  wherever  such  construction  of 
the  term  is  applicable.) 

LICENSES 

REQUIREMENTS 

No  person  shall  engage  in  the  sale,  handling,  or  distribution  of  milk  in 

until  he  has  obtained  a  license  therefor  from  the  health  authorities.  This  license 
shall  be  renewed  on  or  before  the  1st  day  of  —  —  of  each  year  and  may  be 
suspended  or  revoked  at  any  time  for  cause. 

RECOMMENDATIONS 

The  application  for  the  license  shall  include  the  following  statements : 

(1)  Kind  of  milk  to  be  handled  or  sold. 

(2)  Names  of  producers  with  their  addresses  and  permit  numbers. 

(3)  Names  of  middlemen  with  their  addresses. 

(4)  Names  and  addresses  of  all  stores,  hotels,  factories,  and  restaurants  at  which 
milk  is  delivered. 

(5)  A  statement  of  the  approximate  number  of  quarts  of  milk,  cream,  buttermilk, 
and  skim  milk  sold  per  day. 

(6)  Source  of  water  supply  at  farms  and  bottling  plants. 

(7)  Permission  to  inspect  all  local  and  out-of-town  premises  on  which  milk  is  pro- 
duced and  handled. 

(8)  Agreement  to  abide  by  all  the  provisions  of  State  and  local  regulations. 

PERMITS 
REQUIREMENTS 

No  person  shall  engage  in  the  production  of  milk  for  sale  in ,  nor  shall 

any  person  engage  in  the  handling  of  milk  for  shipment  into until  he  has 

obtained  a  permit  therefor  from  the  health  authorities.     This  permit  shall  be 

renewed  on  or  before  the  1st  day  of of  each  year  and  may  be  suspended  or 

revoked  at  any  time  for  cause. 

395 


396  CITY  MILK  SUPPLY 

Production  of  Raw  Milk 

Cow  STABLES 

REQUIREMENTS 

1.  They  shall  be  used  for  no  other  purpose  than  for  the  keeping  of  cows,  and 
shall  be  light,  well  ventilated,  and  clean. 

2.  They  shall  be  ceiled  overhead  if  there  is  a  loft  above. 

3.  The  floors  shall  be  tight  and  sound. 

4.  The  gutters  shall  be  water-tight. 

RECOMMENDATIONS 

1.  The  window  area  shall  beat  least  2  sq.  ft.  per  500  cu.  ft.  of  air  space  and 
shall  be  uniformly  distributed,  if  possible.     If  uniform  distribution  is  impossible, 
sufficient  additional  window  area  must  be  provided  so  that  all  portions  of  the  barn 
shall  be  adequately  lighted. 

2.  The  amount  of  air  space  shall  be  at  least  500  cu.  ft.  per  cow,  and  adequate 
ventilation  besides  windows  shall  be  provided. 

3.  The  walls  and  ceilings  shall  be  whitewashed  at  least  once  every  6  months, 
unless  the  construction  renders  it  unnecessary,  and  shall  be  kept  free  from  cobwebs 
and  dirt. 

4.  All  manure  shall  be  removed  at  least  twice  daily,  and  disposed  of  so  as  not  to 
be  a  source  of  danger  to  the  milk  either  as  furnishing  a  breeding  place  for  flies  or 
otherwise. 

5.  Horse  manure  shall  not  be  used  in  the  cow  stable  for  any  purpose. 

REQUIREMENTS 

Every  milk  farm  shall  be  provided  with  a  milk  room  that  is  clean,  light,  and 
well  screened.  It  shall  be  used  for  no  other  purpose  than  for  the  cooling,  bottling, 
and  storage  of  milk  and  the  operations  incident  thereto. 

RECOMMENDATIONS 

1.  It  shall  have  no  direct  connection  with  any  stable  or  dwelling. 

2.  The  floors  shall  be  of  cement  or  other  impervious  material,  properly  graded  and 
drained. 

3.  It  shall  be  provided  with  a  sterilizer  unless  the  milk  is  sent  to  a  bottling  plant, 
in  which  case  the  cans  shall  be  sterilized  at  the  plant. 

4.  Cooling  and  storage  tanks  shall  be  drained  and  cleaned  at  least  twice  each  week. 

5.  All  drains  shall  discharge  at  least  100  ft.  from  any  milk  house  or  cow  stable. 

Cows 

REQUIREMENTS 

1.  A  physical  examination  of  all  cows  shall  be  made  at  least  once  every  six 
months  by  a  veterinarian  approved  by  the  health  authorities. 

2.  Every  diseased  cow  shall  be  removed  from  the  herd  at  once  and  no  milk 
from  such  cows  shall  be  offered  for  sale. 

3.  The  tuberculin  test  shall  be  applied  at  least  once  a  year  by  a  veterinarian 
approved  by  the  health  authorities. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  397 

4.  All  cows  which  react  shall  be  removed  from  the  herd  at  once,  and  no  milk 
from  such  cows  shall  be  sold  as  raw  milk. 

5.  No  new  cows  shall  be  added  to  a  herd  until  they  have  passed  a  physical 
examination  and  the  tuberculin  test. 

6.  Cows,  especially  the  udders,  shall  be  clean  at  the  time  of  milking. 

7.  No  milk  that  is  obtained  from  a  cow  within  15  days  before  or  5  days  after 
parturition,  nor  any  milk  that  has  an  unnatural  odor  or  appearance,  shall  be  sold. 

8.  No  unwholesome  food  shall  be  used. 

RECOMMENDATIONS 

1.  Every  producer  shall  allow  a  veterinarian  employed  by  the  health  authorities 
to  examine  his  herd  at  any  time  under  the  penalty  of  having  his  supply  excluded. 

2.  Certificates  showing  the  results  of  all  examinations  shall  be  filed  with  the  health 
authorities  within  10  days  of  such  examinations. 

3.  The  tuberculin  tests  shall  be  applied  at  least  once  every  6  months  by  a  veteri- 
narian approved  by  the  health  authorities,  unless  on  the  last  previous  test  no  tubercu- 
losis was  present  in  the  herd  or  in  the  herds  from  which  new  cows  were  obtained, 
in  which  event  the  test  may  be  postponed  an  additional  6  months. 

4.  Charts  showing  the  results  of  all  tuberculin  tests  shall  be  filed  with  the  health 
authorities  within  10  days  of  the  date  of  such  test. 

5.  The  udders  shall  be' washed  and  wiped  before  milking. 

EMPLOYEES 
REQUIREMENTS 

1.  All  employees  connected  in  any  way  with  the  production  and  handling  of 
milk  shall  be  personally  clean  and  shall  wear  clean  outer  garments. 

3.  The  health  authorities  shall  be  notified  at  once  of  any  communicable  dis- 
ease in  any  person  that  is  in  any  way  connected  with  the  production  or  handling 
of  milk,  or  of  the  exposure  of  such  person  to  any  communicable  disease. 

3.  Milking  shall  be  done  only  with  dry  hands. 

RECOMMENDATIONS 

1.  Clean  suits  shall  be  put  on  immediately  before  milking. 

2.  The  hands  shall  be  washed  immediately  before  milking  each  cow,  in  order  to 
avoid  conveyance  of  infection  to  the  milk. 

UTENSILS 
REQUIREMENTS 

1.  All  utensils  and  apparatus  with  which  milk  comes  in  contact  shall  be  thor- 
oughly washed  and  sterilized,  and  no  milk  utensil  or  apparatus  shall  be  used  for 
any  other  purpose  than  that  for  which  it  was  designed. 

2.  The  owner's  name,  license  number,  or  other  identification  mark,  the  nature 
of  which  shall  be  made  known  to  the  health  authorities,  shall  appear  in  a  con- 
spicuous place  on  every  milk  container. 

3.  No  bottle  or  can  shall  be  removed  from  a  house  in  which  there  is,  or  in 
which  there  has  recently  been,  a  case  of  communicable  disease  until  permission 
in  writing  has  been  granted  by  the  health  authorities. 


398  CITY  MILK  SUPPLY 

4.  All  metal  containers  and  piping  shall  be  in  good  condition  at  all  times. 
All  piping  shall  be  sanitary  milk  piping,  in  couples  short  enough  to  be  taken 
apart  and  cleaned  with  a  brush. 

5.  Small-top  milking  pails  shall  be  used. 

RECOMMENDATIONS 

1.  All  cans  and  bottles  shall  be  cleaned  as  soon  as  possible  after  being  emptied. 

2.  Every  conveyance  used  for  the  transportation  or  delivery  of  milk,  public  car- 
riers excepted,  shall  bear  the  owner's  name,  milk-license  number,  and  business  address 
in  uncondensed  gothic  characters  at  least  2  in.  in  height. 

HANDLING  OF  MILK 
REQUIREMENTS 

1.  It  shall  not  be  strained  in  the  cow  stable,  but  shall  be  removed  to  the  milk 
room  as  soon  as  it  is  drawn  from  the  cow. 

2.  It  shall  be  cooled  to  50°F.  or  below  within  two  hours  after  it  is  drawn  from 
the  cow  and  it  shall  be  kept  cold  until  it  is  delivered  to  the  consumer. 

3.  It  shall  not  be  adulterated  by   the  addition  or  the  subtraction  of  any 
substance  or  compound,  except  for  the  production  of  the  fluid  derivatives  allowed 
by  law. 

4.  It  shall  not  be  tested  by  taste  at  any  bottling  plant,  milk  house,  or  other 
place  in  any  way  that  may  render  it  liable  to  contamination. 

5.  It  shall  be  bottled  only  in  a  milk  room  or  bottling  plant  for  which  a  license 
or  permit  has  been  issued. 

6.  It  shall  be  delivered  in  bottles,  or  single  service  containers,  with  the  excep- 
tion that  20  qt.  or  more  may  be  delivered  in  bulk  in  the  following  cases: 

(a)  To  establishments  in  which  milk  is  to  be  consumed  or  used  on  the  premises. 
(6)  To  infant-feeding  stations  that  are  under  competent  medical  supervision. 

7 .  It  shall  not  be  stored  in  or  sold  from  a  living  room  or  from  any  other  place 
which  might  render  it  liable  to  contamination. 

RECOMMENDATIONS 

1.  It  shall  be  cooled  to  50°F.  or  below  immediately  after  milking  and  shall  be  kept 
at  or  below  that  temperature  until  it  is  delivered  to  the  consumer. 

2.  It  shall  contain  no  visible  foreign  material. 

3.  It  shall  be  labeled  with  the  date  of  production.  ,,'j 

RECEIVING  STATIONS  AND  BOTTLING  PLANTS 
REQUIREMENTS 

1.  They  shall  be  clean,  well  screened,  and  lighted,  and  shall  be  used  for  no 
other  purpose  than  the  proper  handling  of  milk  and  the  operations  incident 
thereto,  and  shall  be  open  to  inspection  by  the  health  authorities  at  any  time. 

2.  They  shall  have  smooth,  impervious  floors,  properly  graded  and  drained. 

3.  They  shall  be  equipped  with  hot  and  cold  water  and  steam. 

4.  Ample  provision  shall  be  made  for  steam  sterilization  of  all  utensils,  and 
no  empty  milk  containers  shall  be  sent  out  until  after  such  sterilization. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  399 

5.  All  utensils,  piping,  and  tanks  shall  be  kept  clean  and  shall  be  sterilized 
daily. 

RECOMMENDATIONS 

1.  Containers  and  utensils  shall  not  be  washed  in  the  same  room  in  which  milk  is 
handled. 

STORES 
REQUIREMENTS 

1.  All  stores  in  which  milk  is  handled  shall  be  provided  with  a  suitable  room 
or  compartment  in  which  the  milk  shall  be  kept.     Said  compartment  shall  be 
clean  and  shall  be  so  arranged  that  the  milk  will  not  be  liable  to  contamination 
of  any  kind. 

2.  Milk  shall  be  kept  at  a  temperature  not  exceeding  50°F. 

RECOMMENDATIONS 

1.  Milk  to  be  consumed  off  the  premises  may  be  sold  from  stores  only  in  the  original 
unopened  package. 

GENERAL  REGULATIONS 
REQUIREMENTS 

1.  The  United  States  Bureau  of  Animal  Industry  score  card  shall  be  used, 
and  it  is  recommended  that  dairies  from  which  milk  is  to  be  sold  in  a  raw  state 
shall  score  at  least  80  points. 

2.  Every  place  where  milk  is  produced  or  handled  and  every  conveyance 
used  for  the  transportation  of  milk  shall  be  clean. 

3.  All  water  supplies  shall  be  from  uncontaminated  sources  and  from  sources 
not  liable  to  become  contaminated. 

4.  The  license  or  permit  shall  be  kept  posted  in  a  conspicuous  place  in  every 
establishment  for  the  operation  of  which  a  milk  license  or  permit  is  required. 

5.  No  milk  license  or  permit  shall  at  any  time  be  used  by  any  person  other 
than  the  one  to  whom  it  was  granted. 

6.  No  place  for  the  operation  of  which  a  license  or  permit  is  granted  shall 
be  located  within  100  ft.  of  a  privy  or  other  possible  source  of  contamination, 
nor  shall  it  contain  or  open  into  a  room  which  contains  a  water-closet. 

7.  No  skim-milk  or  buttermilk  shall  be  stored  in  or  sold  from  cans  or  other 
containers  unless  such  containers  are  of  a  distinctive  color  and  permanently  and 
conspicuously  labeled  " skim-milk"  or  "buttermilk,"  as  the  case  may  be. 

8.  No  container  shall  be  used  for  any  other  purpose  than  that  for  which  it  is 
labeled. 

RECOMMENDATIONS 

1.  Ice  used  for  cooling  purposes  shall  be  clean  and  uncontaminated. 

2.  'No  person  whose  presence  is  not  required  shall  be  permitted  to  remain  in  any 
cow  stable,  milk  house,  or  bottling  room. 


400  CITY  MILK  SUPPLY 

SUBNORMAL  MILK 
REQUIREMENTS 

1.  Natural  milk  that  contains  less  than  3.25  per  cent.,  but  more  than  2.5  per 
cent,  milk  fat,  and  that  complies  in  all  other  respects  with  the  requirements  above 
set  forth,  may  be  sold,  provided  the  percentage  of  fat  does  not  fall  below  a  definite 
percentage  that  is  stated  in  a  conspicuous  manner  on  the  container;  and  further 
provided  that  such  container  is  conspicuously  marked  "substandard  milk." 

PRODUCTION  OF  CREAM 
REQUIREMENTS  AND  RECOMMENDATIONS 

1.  It  shall  be  obtained  from  milk  that  is  produced  and  handled  in  accordance 
with  the  provisions  hereinbefore  set  forth  for  the  production  and  handling  of 
milk. 

STANDARDS  FOR  MILK 

REQUIREMENTS 

1.  It  shall  not  contain  more  than  100,000  bacteria  per  cubic  centimeter. 

2.  It  shall  contain  not  less  than  3.25  per  cent,  milk  fat. 

3.  It  shall  contain  not  less  than  8.5  per  cent,  solids-not-fat. 

RECOMMENDATIONS 

1.  The  bacterial  limit  shall  be  lowered  if  possible. 
STANDARDS  FOR  CREAM 
REQUIREMENTS 

1.  There  shall  be  a  bacterial  standard  for  cream  corresponding  to  the  grade 
of  milk  from  which  it  is  made  and  to  its  butterfat  content. 

2.  It  shall  contain  not  less  than  18  per  cent,  milk  fat. 

RECOMMENDATIONS 

Same  as  above  for  milk. 

STANDARDS  FOR  SKIM-MILK 
REQUIREMENTS 

1.  It  shall  contain  not  less  than  8.75  per  cent,  milk  solids. 

2.  Control  of  sale  of  skim-milk:  Whether]  skim-milk  is  sold  in  wagons  or  in 
stores  all  containers  holding  skim-milk  should  be  painted  some  bright,  distinctive 
color  and  prominently  and  legibly  marked  "  skim-milk."     When  skim-milk  is 
placed  in  the  buyer's  container,  a  label  or  tag  bearing  the  words  "skim-milk" 
should  be  attached. 

PRODUCTION  OF  PASTEURIZED  MILK 

Pasteurized  milk  is  milk  that  is  heated  to  a  temperature  of  not  less  than  140°F. 
for  not  less  than  20  min.,  or  not  over  155°F.  for  not  less  than  5  min.,  and  for 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  401 

each  degree  of  temperature  over  140°F.  the  length  of  time  may  be  1  min.  less 
than  20.  Said  milk  shall  be  cooled  immediately  to  50°F.  or  below  and  kept 
at  or  below  that  temperature. 

Cow  STABLES 

REQUIREMENTS 

The  same  as  for  the  production  of  raw  milk. 

RECOMMENDATIONS 

The  same  as  for  the  production  of  raw  milk. 

MILK  ROOM 
REQUIREMENTS 
The  same  as  for  the  production  of  raw  milk. 

RECOMMENDATIONS 

The  same  as  for  the  production  of  raw  milk. 

Cows 

REQUIREMENTS 

The  same  as  for  the  production  of  raw  milk,  with  the  exception  of  the  sections 
relating  to  the  tuberculin  test. 

RECOMMENDATIONS 

That  no  cows  be  added  to  a  herd  excepting  those  found  to  be  free  from  tuberculosis 
by  the  tuberculin  test. 

EMPLOYEES 

REQUIREMENTS 
The  same  as  for  the  production  of  raw  milk, 

RECOMMENDATIONS 

The  same  as  for  the  production  of  raw  milk. 

UTENSILS 
REQUIREMENTS 
The  same  as  for  the  production  of  raw  milk. 

RECOMMENDATIONS 

The  same  as  for  the  production  of  raw  milk. 

MILK  FOR  PASTEURIZATION 
REQUIREMENTS 

1.  The  same  as  for  the  production  of  raw  milk,  with  the  exception  of  sections 
1,  2,  and  66. 

26 


402  CITY  MILK  SUPPLY 

2.  It  shall  be  cooled  to  60°F.  or  below  within  two  hours  after  it  is  drawn  from 
the  cow,  and  it  shall  be  held  at  or  below  that  temperature  until  it  is  pasteurized. 
After  pasteurization,  it  vshall  be  held  at  a  temperature  not  exceeding  50°F.  until 
delivered  to  the  consumer. 

3.  Pasteurized  milk  shall  be  distinctly  labeled  as  such,  together  with  the 
temperature  at  which  it  is  pasteurized  and  the  shortest  length  of  exposure  to 
that  temperature  and  the  date  of  pasteurization. 

RECOMMENDATIONS 

1.  No  milk  shall  be  repasteurized. 

2.  The  requirements  governing  the  production  and  handling  of  milk  for  pasteuri- 
zation should  be  raised  wherever  practicable. 

PASTEURIZING  PLANTS 

REQUIREMENTS 
The  same  as  under  "Receiving  stations  and  bottling  plants"  for  raw  milk. 

RECOMMENDATIONS 

The  same  as_under  "Receiving  stations  and  bottling  plants"  for  raw  milk. 

STORES 

REQUIREMENTS 
The  same  as  for  raw  milk. 

RECOMMENDATIONS 

The  same  as  for  raw  milk. 

GENERAL  REGULATIONS 

.  '<^f 

REQUIREMENTS 

1.  It  is  recommended  that  dairies  producing  milk  which  is  to  be  pasteurized 
shall  be  scored  on  the  United  States  Bureau  of  Animal  Industry  score  card,  and 
that  health  departments,  or  the  controlling  departments  whatever  they  may  be, 
strive  to  bring  these  scores  up  as  rapidly  as  possible. 

2.  Milk  from  cows  that  have  been  rejected  by  the  tuberculin  test,  but  which 
show  no  physical  signs  of  tuberculosis,  as  well  as  those  which  have  not  been  tested, 
may  be  sold  provided  that  it  is  produced  and  handled  in  accordance  with  all  the 
other  requirements  herein  set  forth  for  pasteurized  milk. 

3.  Ice  used  for  cooling  purposes  shall  be  clean. 

RECOMMENDATIONS 

The  same  as  for  raw  milk. 

PRODUCTION  OF  PASTEURIZED  CREAM 
REQUIREMENTS 

1.  It  shall  be  obtained  only  from  milk  that  could  legally  be  sold  as  milk 
under  the  requirements  hereinbefore  set  forth. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY       .     403 

2.  Pasteurized  cream,  or  cream  separated  from  pasteurized  milk,  shall  be 
labeled  in  the  manner  herein  provided  for  the  labeling  of  pasteurized  milk. 

STANDARDS  FOR  PASTEURIZED  MILK 
REQUIREMENTS 

1.  It  shall  not  contain  more  than  1,000,000  bacteria  per  cubic  centimeter 
before  pasteurization,  nor  over  50,000  when  delivered  to  the  consumer. 

2.  The  standards  for  the  percentage  of  milk  fat  and  of  total  solids  shall  be 
the  same  as  for  raw  milk. 

RECOMMENDATIONS 

1.  The  limits  for  the  bacterial  count  before  pasteurization  and  after  pasteurization 
should  both  be  lowered  if  possible. 

STANDARDS  FOR  PASTEURIZED  CREAM 
REQUIREMENTS 

1.  No  cream  shall  be  sold  that  is  obtained  from  pasteurized  milk  that  could 
not  be  legally  sold  under  the  provisions  herein  set  forth,  nor  shall  any  cream  that 
is  pasteurized  after  separation  contain  an  excessive  number  of  bacteria. 

2.  There  shall  be  a  bacterial  standard  for  pasteurized  cream  corresponding 
to  the  grade  of  milk  from  which  it  is  made  and  to  its  butterfat  content. 

3.  The  percentage  of  milk  fat  shall  be  the  same  as  for  raw  cream. 

Production  of  Certified  Milk. — The  production  of  certified  milk  is 
conducted  in  a  way  that  is  intended  to  assure  a  product  of  exceptional 
cleanliness  and  purity  for  the  use  of  infants  and  invalids.  Ernest  Kelly 
in  Bulletin  1  of  the  U.  S.  Department  of  Agriculture  has  taken  up  "  Med- 
ical Milk  Commissions  and  Certified  Milk"  and  the  brief  account  of  the 
work  of  certified  dairies  that  follows  is  principally  drawn  from  his  bulletin. 
Certified  milk  is  the  result  of  the  effort  of  the  Medical  Society  of  New 
Jersey  to  improve  the  milk  supply  of  that  State.  In  1889  the  Society 
appointed  a  committee  to  investigate  the  public  health  aspect  of  dairying 
in  New  Jersey  with  the  outcome  that  after  2  years'  work  the  committee 
made  a  report  which  was  the  basis  of  an  appeal  to  the  State  to  undertake 
the  supervision  of  the  dairies  within  its  limits.  The  desirability  of  doing 
so  was  admitted  by  the  authorities  but  the  appeal  was  denied  on  the 
ground  of  lack  of  funds. 

Then  in  1892  Dr.  Henry  L.  Coit,  the  chairman  of  the  Committee  pre- 
sented a  plan  to  the  Practitioner's  Club  of  Newark  whereby  the  physicians 
themselves  could  control  the  production  of  milk.  It  was  recommened 
that  the  physicians  should  form  a  commission  that  should  certify  the  milk 
produced  in  accordance  with  their  requirements.  The  Club  accepted 
the  report  and  on  April  13,  1893,  organized  the  first  milk  commission. 
It  was  composed  of  physicians  of  Newark,  Orange  and  Montclair  and 
adopted  the  name  of  "The  Medical  Milk  Commission  of  Essex  County, 
New  Jersey."  A  contract  was  made  with  Stephen  Francisco,  proprietor 


404  CITY  MILK  SUPPLY 

of  the  Fairfield  Dairy  of  Montclair  for  the  production  of  the  milk.  The 
term  " certified  milk"  proposed  by  Dr.  Coit,  was  adopted  and  later,  on 
Oct.  18,  1904,  at  the  instance  of  Mr.  Francisco  the  word  "certified"  was 
registered  in  the  U.  S.  Patent  office  under  registry  number  25,368  to 
protect  the  word  from  being  used  by  dairymen  not  working  under  a  med- 
ical milk  commission  but  with  the  understanding  that  it  might  be  em- 
ployed without  question  by  all  such  commissions.  So,  certified  milk  is 
properly  only  that  milk  which  is  produced  under  the  direction  of  a  Med- 
ical Milk  Commission,  usually  appointed  by  the  County  or  State  Med- 
ical Society.  In  New  Jersey,  New  York,  and  some  other  States  only  milk 
that  is  so  produced  can  legally  be  sold  as  certified  milk  but  elsewhere 
dealers  may  impose  on  the  public  by  selling  a  milk  which  they  certify 
themselves,  or  get  someone  else  to,  as  certified  milk. 

This  first  commission  was  successful  and  was  soon  overwhelmed  by 
correspondence  from  all  parts  of  the  United  States,  relative  to  the  mode 
of  establishing  and  conducting  the  certified  milk  business  and  other  early 
commissions  were  burdened  in  the  same  way.  This  led  to  Dr.  Otto  P. 
Geier  of  Cincinnati  proposing  a  conference  of  the  commissions  which  was 
held  at  the  meeting  of  the  American  Medical  Association  at  Atlantic 
City,  N.  J.,  on  June  3,  1907.  A  permanent  organization  under  the  name 
of  the  American  Association  of  Medical  Milk  Commission  was  effected 
with  Dr.  Coit  as  President  and  Dr.  Geier  as  Secretary.  Annual  confer- 
ences have  been  held  since  that  time  and  to  date  the  instructive  proceed- 
ings of  eight  conferences  have  been  issued  by  the  Association.  This  first 
conference  marked  an  important  forward  step  in  bettering  the  milk 
supplies  of  the  country  for  committees  were  appointed  to  investigate 
many  different  phases  of  dairying  and  so  the  forces  that  were  working  for 
better  milk  became  organized  and  found  national  expression. 

The  influence  of  these  medical  milk  commissions  has  been  very  great. 
In  the  first  place  they  have  furnished  clean  pure  milk  to  physicians  for 
the  use  of  children  and  invalids  and  in  the  second  they  have  demonstrated 
that  it  was  possible  to  produce  and  market  a  milk  of  superior  flavor  and 
keeping  qualities.  In  the  third,  their  direct  and  indirect  influence  on 
other  dairies  has  been  very  important  for  some  commissions  have  in- 
spected other  dairies  in  their  vicinity  that  were  not  producing  certified 
milk  and  enabled  the  satisfactory  ones,  with  their  approval,  to  market 
milk  under  an  "  inspected"  label  and  the  equipment  and  methods  of  their 
certified  dairies  have  served  as  models  for  other  dairymen.  Finally,  they 
arouse  public  interest  in  pure  milk  for  physicians  practising  in  their  vicin- 
ity are  alive  to  its  importance  and  the  people  by  contact  with  these  men 
and  often  by  literature  furnished  by  the  commissions  learn  the  value  of 
pure  milk  and  make  some  effort  to  secure  it  for  their  families. 

It  should  be  understood  that  certified  milk  has  no  unusual  properties 
other  than  those  of  exceptional  cleanliness  and  purity.  It  is  the  process 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


405 


of  production  of  the  milk  that  is  certified  to  and  not  either  the  exact  com- 
position of  the  milk  or  its  absolute  freedom  from  morbific  principles. 
Certified  milk  is  produced  from  all  sorts  of  cattle  from  natives  to  grades 
to  purebreds  of  the  five  principal  dairy  breeds  so  that  the  composition 
of  the  milk  must  inevitably  vary.  By  insisting  on  veterinary  inspection 
of  the  herds,  on  their  being  kept  in  proper  surroundings,  on  their  being  fed 
wholesome  rations  and  tended  by  healthy  employees  and  by  seeing  to  it 
that  the  milk  is  properly  handled  and  transported  the  commissions  offer 
to  the  public  a  raw  milk  that  is  very  unlikely  to  be  unwholesome  or  in- 
fected, nevertheless  it  is  impossible  to  guarantee  that  some  cow  with  an 
undetected  udder  ailment  or  some  bacillus  carrier  or  mildly  sick  person 
has  not  infected  it.  The  fact  that  certified  dairies  have  very  seldom  been 
connected  in  any  way  with  outbreaks  of  communicable  disease  shows 
that  the  danger  of  the  milk  being  infected  is  very  slight;  still  there  are 
some  who  would  pasteurize  certified  milk. 

The  high  quality  of  milk  that  may  be  produced  by  certified  dairies 
has  recently  been  shown  by  Kelly,  who  has  given  out  the  results  of  the 
scoring  of  milk  by  the  U.  S.  Department  of  Agriculture  in  cream  contests 
wherein  both  certified  and  market  milks  have  been  entered.  These 
scores  are  given  in  Table  116. 

TABLE  116. — AVERAGE  SCORES  OF  CERTIFIED  AND  MARKET  MILK  IN  MILK  AND 

CREAM  CONTESTS  (KELLY) 


Possible 
score 

Certified 

Market 

Possible 
score 

Certified 

Market 

Bacteria  

35  00 

30  45 

23   87 

35  00 

29  37 

21    32 

Flavor  and  odor 

25  00 

19  50 

20  05 

25  00 

20  11 

19  26 

Visisble  dirt  
Fat 

10.00 
10  00 

8.85 
9  64 

8.36 
-9  13 

10.00 
20  00 

9.37 
19  53 

8.77 
19  75 

Solids-not-fat  

10.00 

9.84 

9.47 

Acidity     ... 

5  00 

4  73 

4  62 

5  00 

4  74 

4  70 

Bottle  and  top  

5.00 

4.95 

4.53 

5  00 

4  80 

4  62 

Total  

100  00 

87  96 

80  05 

100  00 

87  82 

78  42 

These  scores  presumably  represent  the  products  at  their  best.  It 
appears  that  on  the  bacterial  count  the  certified  milk  scored  nearly  *7 
points  higher  than  the  market  milk,  and  led  it  in  all  other  respects  except 
in  flavor  in  which  it  fell  behind  half  a  point.  Certified  cream  scored  8 
points  higher  than  market  cream  and  was  superior  to  it  in  every  other  way 
except  fat  content  in  which  it  was  less  than  1  point  behind. 

It  is  required  that  all  certified  milk  shall  reach  the  consumer  within 
30  hr.  after  milking  but  it  easily  keeps  sweet  much  longer  than  that. 
Occasionally  it  is  put  aboard  ocean  liners  by  travelers  to  Europe  who  have 
it  kept  cold  and  use  it  throughout  the  voyage.  At  the  Paris  exposition 
in  1900  certified  milk  from  the  United  States,  to  the  astonishment  of  the 


406 


CITY  MILK  SUPPLY 


judges,  was  placed  on  exhibition  in  perfectly  sweet  condition  after  a 
journey  of  14  to  18  days  over  3,000  to  4,000  miles  in  midsummer.  One 
producer  told  this  writer  that  some  of  his  milk  was  sweet  and  was  drunk 
with  relish  in  Labrador  7  weeks  after  it  was  produced.  At  the  National 
Dairy  Shows  and  various  expositions  certified  milk  from  all  parts  of  the 
United  States  and  Canada  is  put  on  exhibition  with  a  low  bacterial  count. 


Courtesy  of  Stephen  Francisco. 

FIG.  60. — Producing  certified  milk  in  the  shed  barn  of  the  Fairfield  Dairy  at  Cald- 
well,  N.  J.  Several  barn  operations  such  as  washing  and  drying  the  cows  udders  and 
the  use  of  a  vacuum  cleaner  for  cleaning  the  cows,  are  shown. 

It  is  of  course  inadvisable  to  drink  old  milk  because  it  may  support  a 
growth  of  noxious  germs  that  are  indetectable  by  taste. 

Certified  milk  is  produced  in  buildings  of  approved  construction 
many  of  which  are  very  expensive  but  enough  has  been  produced  in 
moderate-priced  structures  to  show  that  a  costly  plant  is  unnecessary. 
Thorough  sanitation  is  maintained;  the  37  certified  farms  scored  by  the 
U.  S.  Department  of  Agriculture  had  an  average  score  of  about  90  and 
that  the  lowest  score  on  record  in  the  department  of  any  certified  dairy 
is  73.6. 

The  cows  from  which  certified  milk  is  produced  are  tuberculin-tested; 
the  bedding  is  usually  of  sawdust,  or  shavings;  the  cows  are  generally 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  407 

fed  after  milking:  pastures  and  barnyards  are  well-drained;  particular 
attention  is  paid  to  the  utensils;  small-top  pails  are  almost  always  used; 
the  cows  are  carefully  groomed  long  enough  before  milking  to  let  the 
dust  settle ;  milkers  scrub  up  thoroughly  before  starting  to  milk  and  wear 
clean  suits  consisting  of  overalls,  jumpers  and  caps;  as  each  cow  is  milked 
her  milk  is  brought  to  the  milk  room  where  it  is  strained;  under  the  best 
management  the  milkers  wash  their  hands  before  milking  the  next  cow. 
The  milk  is  cooled  either  before  or  after  bottling.  The  bottle  caps  are  of  a 
style  that  completely  cover  the  top  of  the  bottle  and  many  dairies  use  a 
double  cap.  The  caps  are  sterilized  by  dry  heat  before  being  used.  In 
transit  the  milk  is  kept  cold.  Some  certified  dairies  deliver  their  own 
milk  while  others  distribute  it  through  a  city  milk  dealer. 

Kelly  states  that  in  a  study  of  92  certified  dairies  in  17  States  he  found 
that  the  number  of  cows  to  a  herd  varied  from  9  to  600  and  that  the  aver- 
age was  88.  The  amount  of  milk  handled  ranged  from  12.5  to  6,000  qt. 
and  averaged  747.5  qt.  The  average  production  per  cow  per  day  was  8.3 
qt.  which  was  above  that  of  the  cows  in  market  dairies  but  which  he  regards 
as  lower  than  it  should  be.  The  bacterial  count  of  certified  dairies  varies 
up  to  30,000  per  cubic  centimeter,  probably  most  of  them  expect  to  keep 
it  below  10,000  per  cubic  centimeter.  In  this  study  one  of  the  dairies 
reported  that  its  plates  ran  from  sterile  to  1,000  per  cubic  centimeter, 
and  three  reported  counts  of  20,000  per  cubic  centimeter,  but  the  average 
of  all  was  4,069  per  cubic  centimeter.  It  was  stated  that  a  few  of  the 
producers  put  their  milk  on  the  market  when  it  was  6  hr.  most  when  it 
was  20  hr.  and  a  few  others  when  it  was  48  hr.  old. 

Kelly  estimates  that  in  1912  the  total  production  of  certified  milk 
per  day  was  25,000  gal.  which  was  a  300  per  cent,  increase  since  1907. 
Among  43  active  commissions  that  replied  to  his  queries  the  most  milk, 
certified  per  day  by  a  single  one,  was  10,752  qt. 

It  is  probable  that  in  none  of  our  large  cities  does  the  production  of 
certified  milk  greatly  exceed  1  per  cent,  of  the  total  supply.  The  reason 
for  this  is  the  high  price  asked  for  certified  milk.  It  nearly  always  costs 
more  than  most  milk  users  can  afford  to  pay.  So  certified  milk  solves 
the  milk  question  only  for  the  wealthy.  Undoubtedly  it  is  expensive  to 
produce  certified  milk  but  it  seems  certain  that  in  the  past  certified 
dairies  in  general  have  not  been  managed  in  the  most  economical  and  effi- 
cient way  possible.  This  has  had  a  bad  effect  in  two  ways:  it  has  limited 
the  field  of  activity  of  medical  milk  commissions  and  it  has  tended  to 
discourage  dairymen  from  making  the  effort  to  adopt  sanitary  measures 
and  produce  a  high  grade  of  market  milk.  It  is  desirable  that  the  business 
side  of  dairying  be  more  strongly  emphasized  by  the  commissions  in  the 
future. 

In  doing  this  it  would  seem  that  expensive  building  and  unnecessary 
apparatus  should  be  tabooed  and  that  an  effort  should  be  made  to  cheapen 


408  CITY  MILK  SUPPLY 

production  by  attempting  to  control  only  those  sources  of  bacterial  con- 
tamination that  the  most  recent  studies  of  barn  contamination  have 
shown  to  be  important.  Such  doctrine  may  be  heretical  but  it  seems 
to  the  writer  that  more  good  would  be  accomplished  by  the  producers 
of  certified  milk,  if  instead  of  striving  to  market  milk  with  bacterial 
counts  of  less  than  10,000  per  cubic  centimeter,  which  few  can  afford  to 
buy,  they  would  be  content  to  keep  the  counts  between  25,000  and 
50,000  per  cubic  centimeter  and  so,  produce  milk  at  less  cost,  that  might 
be  sold  at  a  price  within  the  means  of  a  larger  public. 

The  members  of  milk  commissions  usually  give  their  services  gratis 
and  they  even  pay  for  the  minor  expenses  of  carrying  on  the  work  them- 
selves. Some  money  for  expenses  is  derived  from  a  charge  that  is  made 
for  certification.  This  may  be  at  so  much  per  year  for  each  dairy,  at 
so  much  per  1,000  caps  or  at  so  much  per  quart  of  milk  produced.  The 
salaries  of  the  experts  in  the  service  of  the  commission  are  commonly 
paid  by  the  dairyman. 

The  immediate  control  of  the  production  of  certified  milk  is  in  the 
hands  of  the  medical  milk  commissions  which  certify  it.  The  American 
Association  of  Medical  Milk  Commissions  in  1912  promulgated  the 
following  rules  for  the  production  of  certified  milk. 

HYGIENE  OF  THE  DAIRY 

UNDER  THE  SUPERVISION  AND  CONTROL  OF  THE  VETERINARIAN 

1.  Pastures  or  Paddocks. — Pastures  or  paddocks  to  which  the  cows  have  access 
shall  be  free  from  marshes  or  stagnant  pools,  crossed  by  no  stream  which  might 
become  dangerously  contaminated,  at  sufficient  distances  from  offensive  condi- 
tions to  suffer  no  bad  effects  from  them,  and  shall  be  free  from  plants  which  affect 
the  milk  deleteriously. 

2.  Surroundings  of  Buildings. — The  surroundings  of  all  buildings  shall  be  kept 
clean  and  free  from  accumulations  of  dirt,  rubbish,  decayed  vegetable  or  animal 
matter  or  animal  waste,  and  the  stable  yard  shall  be  well  drained. 

3.  Location  of  Buildings. — Buildings  in  which  certified  milk  is  produced  and 
handled  shall  be  so  located  as  to  insure  proper  shelter  and  good  drainage,  and  at 
sufficient  distance  from  other  buildings,  dusty  roads,  cultivated  and  dusty  fields, 
and  all  other  possible  sources  of  contamination;  provided,  in  the  case  of  unavoid- 
able proximity  to  dusty  roads  or  fields,  the  exposed  side  shall  be  screened  with 
cheese  cloth. 

4.  Construction  of  Stables. — The  stables  shall  be  constructed  so  as  to  facilitate 
the  prompt  and  easy  removal  of  waste  products.     The  floors  and  platforms  shall 
be  made  of  cement  or  other  non-absorbent  material,  and  the  gutters  of  cement 
only.     The  floors  shall  be  properly  graded  and  drained,  and  the  manure  gutters 
shall  be  from  6  to  8  in.  deep  and  so  placed  in  relation  to  the  platform  that  all 
manure  will  drop  into  them. 

5.  The  inside  surface  of  the  walls  and  all  interior  construction  shall  be  smooth, 
with  tight  joints,  and  shall  be  capable  of  shedding  water.     The  ceiling  shall  be 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  409 

of  smooth  material  and  dust-tight.     All  horizontal  and  slanting  surfaces  which 
might  harbor  dust  shall  be  avoided. 

6.  Drinking  and  Feed  Troughs. — Drinking  troughs  or  basins  shall  be  drained 
and  cleaned  each  day,  and  feed  troughs  and  mixing  floors  shall  be  kept  in  a  clean 
and  sanitary  condition. 

7.  Stanchions. — Stanchions  when  used  shall  be  constructed  of  iron  pipes  or 
hardwood,  and  throat  latches  shall  be  provided  to  prevent  the  cows  from  lying 
down  between  the  time  of  cleaning  and  the  time  of  milking. 

8.  Ventilation. — The  cow  stables  shall  be  provided  with  adequate  ventilation 
either  by  means  of  some  approved  artificial  device,  or  by  the  substitution  of 
cheese  cloth  for  glass  in  the  windows,  each  cow  to  be  provided  with  a  minimum 
of  600  cu.  ft.  of  air  space. 

9.  Windows. — A  sufficient  number  of  windows  shall  be  installed  and  so  dis- 
tributed as  to  provide  satisfactory  light  and  a  maximum  of  sunshine;  2  ft.  square 
of  window  area  to  each  600  cu.  ft.  of  air  space  to  represent  the  minimum. 
The  coverings  of  such  windows  shall  be  kept  free  from  dust  and  dirt. 

10.  Exclusion  of  Flies,  Etc. — All  necessary  measures  should  be  taken  to  pre- 
vent the  entrance  of  flies  and  other  insects,  and  rats  and  other  vermin  into  all  the 
buildings. 

11.  Exclusion  of  Animals  from  the  Herd. — No  horses,  hogs,  dogs,  or  other 
animals  or  fowls  shall  be  allowed  to  come  in  contact  with  the  certified  herd  either 
in  the  stables  or  elsewhere. 

12.  Bedding. — No  dusty  or  mouldy  hay  or  straw,  bedding  from  horse  stalls,  or 
other  unclean  materials  shall  be  used  for  bedding  the  cows.     Only  bedding  which 
is  clean,  dry,  and  absorbent  may  be  used,  preferably  shavings  or  straw. 

13.  Cleaning  Stable  and  Disposal  of  Manure. — Soiled  bedding  and  manure 
shall  be  removed  at  least  twice  daily,  and  the  floors  shall  be  swept  and  kept  free 
from  refuse.     Such  cleaning  shall  be  done  at  least  1  hr.  before  the  milking 
time.     Manure,  when  removed,  shall  be  drawn  to  the  field  or  temporarily  stored 
in  containers  so  screened  as  to  exclude  flies.     Manure  shall  not  be  even  tempo- 
rarily stored  within  300  ft.  of  the  barn  or  dairy  building. 

14.  Cleaning  of  Cows. — Each  cow  in  the  herd  shall  be  groomed  daily,  and  no 
manure,  mud,  or  filth  shall  be  allowed  to  remain  upon  her  during  milking;  for 
cleaning,  a  vacuum  apparatus  is  recommended. 

15.  Clipping. — Long  hairs  shall  be  clipped  from  the  udder  and  flanks  of  the 
cow,  and  from  the  tail  above  the  brush.     The  hair  on  the  tail  shall  be  cut  so  that 
the  brush  may  be  well  above  the  ground. 

16.  Cleaning  of  Udders. — The  udders  and  teats  of  the  cow  shall  be  cleaned 
before  milking;  they  shall  be  washed  with  a  cloth  and  water,  and  dry  wiped  with 
another  clean  sterilized  cloth — a  separate  cloth  for  drying  each  cow. 

17.  Feeding. — All  foodstuffs  shall  be  kept  in  an  apartment  separate  from  and 
not  directly  communicating  with  the  cow  barn.     They  shall  be  brought  into  the 
barn  only  immediately  before  the  feeding  hour,  which  shall  follow  the  milking. 

18.  Only  those  foods  shall  be  used  which  consist  of  fresh,  palatable,  or  nutri- 
tious materials,  such  as  will  not  injure  the  health  of  the  cows  or  unfavorably 
affect  the  taste  or  character  of  the  milk.     Any  dirty  or  mouldy  food  or  food  in 
a  state  of  decomposition  or  putrefaction  shall  not  be  given. 

19.  A  well-balanced  ration  shall  be  used,  and  all  changes  of  food  shall  be  made 


410  CITY  MILK  SUPPLY 

slowly.     The  first  few  feedings  of  grass,  alfalfa,  ensilage,  green  corn,  or  other 
green  feeds  shall  be  given  in  small  rations  and  increased  gradually  to  full  ration. 

20.  Exercise. — All  dairy  cows  shall  be  turned  out  for  exercise  at  least  2  hr. 
in  each  24  in  suitable  weather.     Exercise  yards  shall  be  kept  free  from  manure 
and  other  filth. 

21.  Washing  of  Hands. — Conveniently  located  facilities  shall  be  provided  for 
the  milkers  to  wash  in  before  and  during  milking. 

22.  The  hands  of  the  milkers  shall  be  thoroughly  washed  with  soap,  water, 
and  brush  and  carefully  dried  on  a  clean  towel  immediately  before  milking.     The 
hands  of  the  milkers  shall  be  rinsed  with  clean  water  and  carefully  dried  before 
milking  each  cow.     The  practice  of  moistening  the  hands  with  milk  is  forbidden. 

23.  Milking  Clothes. — Clean  overalls,  jumper,  and  cap  shall  be  worn  during 
milking.     They  shall  be  washed  or  sterilized  each  day  and  used  for  no  other  pur- 
pose, and  when  not  in  use  they  shall  be  kept  in  a  clean  place,  protected  from  dust 
and  dirt. 

24.  Things  to  be  Avoided  by  Milkers. — While  engaged  about  the  dairy  or  in 
handling  the  milk  employees  shall  not  use  tobacco  nor  intoxicating  liquors. 
They  shall  keep  their  fingers  away  from  their  nose  and  mouth,  and  no  milker 
shall  permit  his  hands,  fingers,  lips,  or  tongue  to  come  in  contact  with  milk  in- 
tended for  sale. 

25.  During  milking  the  milkers  shall  be  careful  not  to  touch  anything  but 
the  clean  top  of  the  milking  stool,  the  milk  pail,  and  the  cow's  teats. 

26.  Milkers  are  forbidden  to  spit  upon  the  walls  or  floors  of  stables,  or  upon 
the  walls  or  floors  of  milk  houses,  or  into  the  water  used  for  cooling  the  milk  or 
washing  the  utensils. 

27.  Fore-milk. — The  first  streams  from  each  teat  shall  be  rejected,  as  this 
fore  milk  contains  large  numbers  of  bacteria.     Such  milk  shall  be  collected  into 
a  separate  vessel  and  not  milked  onto  the  floors  or  into  the  gutters.     The  milking 
shall  be  done  rapidly  and  quietly,  and  the  cows  shall  be  treated  kindly. 

28.  Milk  and  Calving  Period. — Milk  from  all  cows  shall  be  excluded  for  a 
period  of  45  days  before  and  7  days  after  parturition. 

29.  Bloody  and  Stringy  Milk. — If  milk  from  any  cow  is  bloody  and  stringy 
or  of  unnatural  appearance,  the  milk  from  that  cow  shall  be  rejected  and  the 
cow  isolated  from  the  herd  until  the  cause  of  such  abnormal  appearance  has  been 
determined  and  removed,  special  attention  being  given  in  the  meantime  to  the 
feeding  or  to  possible  injuries.     If  dirt  gets  into  the  pail,  the  milk  shall  be  dis- 
carded and  the  pail  washed  before  it  is  used. 

30.  Make-up  of  Herd. — No  cows  except  those  receiving  the  same  supervision 
and  care  as  the  certified  herd  shall  be  kept  in  the  same  barn  or  brought  in  con- 
tact with  them. 

31.  Employees  Other  than  Milkers. — The  requirements  for  milkers,  relative 
to  garments  and  cleaning  of  hands,  shall  apply  to  all  other  persons  handling  the 
milk,  and  children  unattended  by  adults  shall  not  be  allowed  in  the  dairy  nor 
in  the  stable  during  milking. 

32.  Straining  and  Strainers. — Promptly  after  the  milk  is  drawn  it  shall  be 
removed  from  the  stable  to  a  clean  room  and  then  emptied  from  the  milk  'pail  to 
the  can,  being  strained  through  strainers  made  of  a  double  layer  of  finely  meshed 
cheese  cloth    or    absorbent    cotton    thoroughly    sterilized.    Several  strainers 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  411 

shall  be  provided  for  each  milking  in   order    that  they  may  be  frequently 
changed. 

33.  Dairy  Building. — A  dairy  building  shall  be  provided  which  shall  be  located 
at  a  distance  from  the  stable  and  dwelling  prescribed  by  the  local  commission, 
and  there  shall  be  no  hogpen,  privy,  or  manure  pile  at  a  higher  level  or  within 
300  ft.  of  it. 

34.  The  dairy  building  shall  be  kept  clean  and  shall  not  be  used  for  purposes 
other  than  the  handling  and  storing  of  milk  and  milk  utensils.     It  shall  be  pro- 
vided with  light  and  ventilation,  and  the  floors  shall  be  graded  and  water-tight. 

35.  The  dairy  building  shall  be  well  lighted  and  screened  and  drained  through 
well-trapped  pipes.     No  animals  shall  be  allowed  therein.     No  part  of  the  dairy 
building  shall  be  used  for  dwelling  or  lodging  purposes,  and  the  bottling  room  shall 
be  used  for  no  other  purpose  than  to  provide  a  place  for  clean  milk  utensils  and 
for  handling  the  milk.     During  bottling  this  room  shall  be  entered  only  by  persons 
employed  therein.     The  bottling  room  shall  be  kept  scrupulously  clean  and  free 
from  odors. 

36.  Temperature  of  Milk. — Proper  cooling  to  reduce  the  temperature  to  45°F. 
shall  be  used,  and  aerators  shall  be  so  situated  that  they  can  be  protected  from 
flies,  dust,  and  odors.     The  milk  shall  be  cooled  immediately  after  being  milked, 
and  maintained  at  a  temperature  between  35°  and  45°F.  until  delivered  to  the 
consumer. 

37.  Sealing  of  Bottles. — Milk,  after  being  cooled  and  bottled,  shall  be  immedi- 
ately sealed  in  a  manner  satisfactory  to  the  commission,  but  such  seal  shall 
include  a  sterile  hood  which  completely  covers  the  lip  of  the  bottle. 

38.  Cleaning  and  Sterilizing  of  Bottles. — The  dairy  building  shall  be  provided 
with  approved  apparatus  for  the  cleansing  and  sterilizing  of  all  bottles  and  uten- 
sils used  in  milk  production.     All  bottles  and  utensils  shall  be  thoroughly  cleaned 
by  hot  water  and  sal  soda,  or  equally  pure  agent,  rinsed  until  the  cleaning  water 
is  thoroughly  removed,  then  exposed  to  live  steam  or  boiling  water  at  least  20 
min.,  and  then  kept  inverted  until  used,  in  a  place  free  from  dust  and  other 
contaminating  materials. 

39.  Utensils. — All  utensils  shall  be  so  constructed  as  to  be  easily  cleaned. 
The  milk  pail  should  preferably  have  an  elliptical  opening  5  by  7  in.  in  diame- 
ter.    The  cover  of  this  pail  should  be  so  convex  as  to  make  the  entire  interior 
of  the  pail  visible  and  accessible  for  cleaning.     The  pail  shall  be  made  of  heavy 
seamless  tin,  and  with  seams  which  are  flushed  and  made  smooth  by  solder. 
Wooden  pails,  galvanized-iron  pails,  or  pails  made  of  rough,  porous  materials,  are 
forbidden.     All  utensils  used  in  milking  shall  be  kept  in  good  repair. 

40.  Water  Supply. — The  entire  water  supply  shall  be  absolutely  free  from 
contamination,  and  shall  be  sufficient  for  all  dairy  purposes.     It  shall  be  protected 
against  flood  or  surface  drainage,  and  shall  be  conveniently  situated  in  relation 
to  the  milk  house. 

41.  Privies,  etc.,  in  Relation  to  Water  Supply. — Privies,  pigpens,  manure  piles, 
and  all  other  possible  sources  of  contamination  shall  be  so  situated  on  the  farm 
as  to  render  impossible  the  contamination  of  the  water  supply,  and  shall  be  so 
protected  by  use  of  screens  and  other  measures  as  to  prevent  their  becoming 
breeding  grounds  for  flies. 

42.  Toilet  Rooms. — Toilet  facilities  for  the  milkers  shall  be  provided  and 


412  CITY  MILK  SUPPLY 

located  outside  of  the  stable  or  milk  house.  These  toilets  shall  be  properly 
screened,  shall  be  kept  clean,  and  shall  be  accessible  to  wash  basins,  water,  nail 
brush,  soap  and  towels,  and  the  milkers  shall  be  required  to  wash  and  dry  their 
hands  immediately  after  leaving  the  toilet  room. 

TRANSPORTATION 

43.  In  transit  the  milk  packages   shall   be   kept  free  from  dust  and  dirt. 
The  wagon,  trays,  and  crates  shall  be  kept  scrupulously  clean.     No  bottles  shall 
be  collected  from  houses  in  which  communicable  diseases  prevail,  unless  a  sepa- 
rate wagon  is  used  and  under  conditions  prescribed  by  the  department  of  health 
and  the  medical  milk  commission. 

44.  All  certified  milk  shall  reach  the  consumer  within  30  hr.  after  milking. 

VETERINARY  SUPERVISION  OF  THE  HERD 

45.  Tuberculin  Test. — The  herd  shall  be  free  from  tuberculosis,  as  shown  by 
the  proper  application  of  the  tuberculin  test.     The  test  shall  be  applied  in  accord- 
ance with  the  rules  and  regulations  of  the  United  States  Government,  and  all 
reactors  shall  be  removed  immediately  from  the  farm.1 

46.  No  new  animals  shall  be  admitted  to  the  herd  without  first  having  passed 
a  satisfactory  tuberculin  test,  made  in  accordance  with  the  rules  and  regulations 
mentioned;  the  tuberculin  to  be  obtained  and  applied  only  by  the  official  veteri- 
narian of  the  commission. 

47.  Immediately  following  the  application  of  the  tuberculin  test  to  a  herd 
for  the  purpose  of  eliminating  tuberculous  cattle,  the  cow  stable  and  exercising 
yards  shall  be  disinfected  by  the  veterinary  inspector  in  accordance  with  the  rules 
and  regulations  of  the  United  States  Government.1 

48.  A  second  tuberculin  test  shall  follow  each  primary  test  after  an  interval 
of  6  months,  and  shall  be  applied  in  accordance  with  the  rules  and  regulations 
mentioned.     Thereafter,  tuberculin  tests  shall  be  reapplied  annually,  but  it  is 
recommended  that  the  retests  be  applied  semiannually. 

49.  Identification  of  Cows. — -Each  dairy  cow  in  each  of  the  certified  herds 
shall  be  labeled  or  tagged  with  a  number  or  mark  which  will  permanently  identify 
her. 

50.  Herd-book  Record. — Each  cow  in  the  herd  shall  be  registered  in  a  herd 
book  which  register  shall  be  accurately  kept  so  that  her  entrance  and  departure 
from  the  herd  and  her  tuberculin  testing  can  be  identified. 

51.  A  copy  of  this  herd-book  record  shall  be  kept  in  the  hands  of  the  veteri- 
narian of  the  medical  milk  commission  under  which  the  dairy  farm  is  operating, 
and  the  veterinarian  shall  be  made  responsible  for  the  accuracy  of  this  record. 

52.  Dates  of  Tuberculin  Tests. — The  dates  of  the  annual  tuberculin  tests  shall 
be  definitely  arranged  by  the  medical  milk  commission,  and  all  of  the  results  of 
such  tests  shall  be  recorded  by  the  veterinarian  and  regularly  reported  to  the 
secretary  of  the  medical  milk  commission  issuing  the  certificate. 

53.  The  results  of  all  tuberculin  tests  shall  be  kept  on  file  by  each  medical 
milk  commission,  and  a  copy  of  all  such  tests  shall  be  made  available  to  the  Ameri- 
can Association  of  Medical  Milk  Commissions  for  statistical  purposes. 

1  See  Circular  of  Instructions  issued  by  the  Bureau  of  Animal  Industry  for  mak- 
ing tuberculin  tests  and  for  disinfection  of  premises. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  413 

54.  The  proper  designated  officers  of  the  American  Association  of  Medical 
Milk  Commissions  should  receive  copies  of  reports  of  all  of  the  annual,  semiannual, 
and  other  official  tuberculin  tests  which  are  made  and  keep  copies  of  the  same  on 
file  and  compile  them  annually  for  the  use  of  the  association. 

55.  Disposition  of  Cows  Sick  with  Diseases  Other  than  Tuberculosis. — Cows 
having  rheumatism,  leukorrhea,  inflammation  of  the  uterus,  severe  diarrhea,  or 
disease  of  the  udder,  or  cows  that  from  any  other  cause  may  be  a  menace  to  the 
herd  shall  be  removed  from  the  herd,  placed  in  a  building  separate  from  that 
which  may  be  used  for  the  isolation  of  cows  with  tuberculosis,  unless  such  build- 
ing has  been  properly  disinfected  since  it  was  last  used  for  this  purpose.     The 
milk  from  such  cows  shall  not  be  used,  nor  shall  the  cows  be  restored  to  the  herd 
until  permission  has  been  given  by  the  veterinary  inspector  after  a  careful  phys- 
ical examination. 

56.  Notification  of  Veterinary  Inspector. — In  the  event  of  the  occurrence  of 
any  of  the  diseases  just  described  between  the  visits  of  the  veterinary  inspector, 
or  if  at  any  time  a  number  of  cows  become  sick  at  one  time  in  such  a  way  as 
to  suggest  the  outbreak  of  a  contagious  disease  or  poisoning,  it  shall  be  the  duty 
of  the  dairyman  to  withdraw  such  sickened  cattle  from  the  herd,  to  destroy 
their  milk,  and  to  notify  the  veterinary  inspector  by  telegraph  or  telephone 
immediately. 

57.  Emaciated  Cows. — Cows  that  are  emaciated  from  chronic  diseases  or  from 
any  cause  that  in  the  opinion  of  the  veterinary  inspector  may  endanger  the  qual- 
ty  of  the  milk,  shall  be  removed  from  the  herd. 

BACTERIOLOGICAL  STANDARDS 

58.  Bacterial  Counts. — Certified  milk  shall  contain  less  than  10,000  bacteria 
per  cubic  centimeter  when  delivered.     In  case  a  count  exceeding  10,000  bacteria 
per  cubic  centimeter  is  found,  daily  counts  shall  be  made,  and  if  normal  counts 
are  not  restored  within  10  days  the  certificate  shall  be  suspended. 

59.  Bacterial  counts  shall  be  made  at  least  once  a  week. 

60.  Collection  of  Samples. — The  samples  to 'be  examined  shall  be  obtained 
from  milk  as  offered  for  sale  and  shall  be  taken  by  a  representative  of  the  milk 
commission.     The  samples  shall  be  received  in  the  original  packages,  in  properly 
iced  containers,  and  they  shall  be  so  kept  until  examined,  so  as  to  limit  as  far  as 
possible  changes  in  their  bacterial  content. 

61.  For  the  purpose  of  ascertaining  the  temperature,  a  separate  original  pack- 
age shall  be  used,  and  the  temperature  taken  at  the  time  of  collecting  the  sample, 
using  for  the  purpose  a  standardized  thermometer  graduated  in  the  centigrade 
scale. 

62.  Interval  between  Milking  and  Plating. — The  examinations  shall  be  made 
as  soon  after  collection  of  the  samples  as  possible,  and  in  no  case  shall  the  interval 
between  milking  and  plating  the  samples  be  longer  than  40  hr. 

63.  Plating. — The  packages  shall  be  opened  with  aseptic  -  precautions  after 
the  milk  has  been  thoroughly  mixed  by  vigorously  reversing  and  shaking  the 
container  25  times. 

64.  Two  plates  at  least  shall  be  made  for  each  sample  of  milk,  and  there 
shall  also  be  made  a  control  of  each  lot  of  medium  and  apparatus  used  at  each 
testing.     The  plates  shall  be  grown  at  37°C.  for  48  hr. 


414  CITY  MILK  SUPPLY 

65.  In  making  the  plates  there  shall  be  used  agar  agar  media  containing  1.5 
per  cent,  agar  and  giving  a  reaction  of  1.0  to  phenolphthalein. 

The  following  is  the  method  recommended  by  a  committee  of  the  American  Public 
Health  Association  for  the  making  of  the  media,  modified,  however,  as  to  the  agar 
content  and  reaction  to  conform  to  the  requirements  specified  in  section  65  (see 
author's  note  at  end  of  the  methods) : 

1.  Boil  15  grams  of  thread  agar  in  500  c.c.  of  water  for  half  an  hour  and  make  up 
weight  to  500  grams  or  digest  for  10  min.  in  the  autoclave  at  1 10°C.     Let  this  cool 
to  about  60°C. 

2.  Infuse  500  grams  finely  chopped  lean  beef  for  24  hr.  with  its  own  weight  of  dis- 
tilled water  in  the  refrigerator. 

3.  Make  up  any  loss  by  evaporation. 

4.  Strain  infusion  through  cotton  flannel,  using  pressure. 

5.  Weigh  filtered  infusion. 

6.  Add  Witte's  peptone,  2  per  cent. 

7.  Warm  on  water  bath,  stirring  until  peptone  is  dissolved  and  not  allowing  tem- 
perature to  rise  above  60°C. 

8.  To  the  500  grams  of  meat  infusion  (with  peptone)  add  500  grams  of  the  2  per 
cent,  agar,  keeping  the  temperature  below  60°C. 

9.  Heat  over  boiling  water  (or  steam)  bath  30  min. 

10.  Restore  weight  lost  by  evaporation. 

11.  Titrate  after  boiling  1  min.  to  expel  carbonic  acid. 

12.  Adjust  reaction  to  final  point  desired  +1  by  adding  normal  sodium  hydrate. 

13.  Boil  2  min.  over  free  flame,  constantly  stirring. 

14.  Restore  weight  lost  by  evaporation. 

15.  Filter  through  absorbent  cotton  or  coarse  filter  paper,  passing  the  filtrate 
through  the  filter  repeatedly  until  clear. 

16.  Titrate  and  record  the  final  reaction. 

17.  Tube  (10  c.c.  to  a  tube)  and  sterilize  in  autoclave  1  hr.  at  15  Ib.  pressure  or  in 
the  streaming  steam  for  20  min.  on  three  successive  days. 

66.  Samples  of  milk  for  plating  shall  be  diluted  in  the  proportion  of  1  part 
of  milk  to  99  parts  of  sterile  water;  shake  25  times  and  plate  1  c.c.  of  the  dilution. 

The  committee  on  bacterial  milk  analyses  of  the  American  Public  Health  Asso- 
ciation in  Part  IV  of  its  report  presented  details  with  respect  to  plating  apparatus 
and  technique  in  part  as  follows: 

Plating  Apparatus. — For  plating  it  is  best  to  have  a  water  bath  in  which  to  melt  the 
media  and  a  water-jacketed  water  bath  for  keeping  it  at  the  required  temperature: 
a  wire  rack  which  should  fit  both  the  water  baths  for  holding  the  media  tubes;  a  ther- 
mometer for  recording  the  temperature  of  the  water  in  the  water-jacketed  bath,  sterile 
1-c.c.  pipettes,  sterile  Petri  dishes,  and  sterile  dilution  water  in  measured  quantities. 

Dilutions. — Ordinary  potable  water,  sterilized,  may  be  used  for  dilutions.  Occa- 
sionally spore  forms  are  found  in  such  water  which  resist  ordinary  autoclave  sterili- 
zation; in  such  cases  distilled  water  may  be  used  or  the  autoclave  pressure  increased. 
With  dilution  water  in  8-oz.  bottles  calibrated  for  99  c.c.  *  *  *  all  the  necessary 
dilutions  may  be  made. 

Short,  wide-mouthed  "blakes"  or  wide-mouthed  French  square  bottles  are  more 
easily  handled  and  more  economical  of  space  than  other  forms  of  bottles  or  flasks. 

Eight-ounce  bottles  are  the  best,  as  the  required  amount  of  dilution  water  only 
about  half  fills  them,  leaving  room  for  shaking.  Long-fiber  non-absorbent  cotton 
should  be  used  for  plugs.  It  is  well  to  use  care  in  selecting  cotton  for  this  purpose 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  415 

to  avoid  short-fiber  or  dusty  cotton,  which  give  a  cloud  of  lint-like  particles  on  shaking. 
Bottles  *  *  *  should  be  filled  a  little  over  the  99  c.c.  *  *  *  to  allow  for  loss  during 
sterilization. 

Pipettes. — Straight  sides  1-c.c.  pipettes  are  more  easily  handled  than  those  with 
bulbs;  they  may  be  made  from  ordinary  %6-in.  glass  tubing  and  should  be  about  10 
in.  in  length. 

Plating  Technique. — The  agar  after  melting  should  be  kept  in  the  water-jacketed 
water  bath  between  40°C.  and  45°C.  for  at  least  15  min.  before  using  to  make 
sure  that  the  agar  itself  has  reached  the  temperature  of  the  surrounding  water.  If 
used  too  warm,  the  heat  may  destroy  some  of  the  bacteria  or  retard  their  growth. 

Shake  the  milk  sample  25  times,  then  with  a  sterile  pipette  transfer  1  c.c.  to  the 
first  dilution  water  and  rinse  the  pipette  by  drawing  dilution  water  to  the  mark  and 
expelling;  this  gives  a  dilution  1  to  100. 

*  *  *  Then  with  a  sterile  pipette  transfer  1  c.c.  to  the  Petri  dish,  using  care  to 
raise  the  cover  only  as  far  as  necessary  to  insert  the  end  of  the  pipette. 

Take  the  tube  of  agar  from  the  water  bath,  wipe  the  water  from  outside  the  tube 
with  a  piece  of  cloth,  remove  the  plug,  pass  the  mouth  of  the  tube  through  a  flame, 
and  pour  the  agar  into  the  plate,  using  the  same  care  as  before  to  avoid  exposure  of  the 
plate  contents  to  the  air. 

Carefully  and  thoroughly  mix  the  agar  and  diluted  milk  in  the  Petri  dish  by  a 
rotary  motion,  avoiding  the  formation  of  air  bubbles  or  slopping  the  agar,  and  after 
allowing  the  agar  to  harden  for  at  least  15  min.  at  room  temperature,  place  the  dish 
bottom  down  in  the  incubator. 

Plating  should  always  be  done  in  a  place  free  from  dust  or  currents  of  air. 

In  order  that  colonies  may  have  sufficient  food  for  proper  development  10  c.c. 
of  agar  shall  be  used  for  each  plate. 

67.  Determination  of  Taste  and  Odor  of  Milk. — After  the  plates  have  been  pre- 
pared and  placed  in  the  incubator,  the  taste  and  odor  of  the  milk  shall  be  deter- 
mined after  warming  the  milk  to  100°F.1 

68.  Counts. — The  total  number  of  colonies  on  each  plate  should  be  counted, 
and  the  results  expressed  in  multiples  of  the  dilution  factor.     Colonies  too  small 
to  be  seen  with  the  naked  eye  or  with  slight  magnification  shall  not  be  considered 
in  the  count. 

69.  Records  of  Bacteriologic  Tests. — The  results  of  all  bacterial  tests  shall  be 
kept  on  file  by  the  secretary  of  each  commission,  copies  of  which  should  be  made 
available  annually  for  the  use  of  the  American  Association  of  Medical  Milk 
Commissions. 

CHEMICAL  STANDARDS  AND  METHODS 

The  methods  that  must  be  followed  in  carrying  out  the  chemical  investigations 
essential  to  the  protection  of  certified  milk  are  so  complicated  that  in  order  to  keep  the 
fees  of  the  chemist  at  a  reasonable  figure,  there  must  be  eliminated  from  the  exami- 
nation those  procedures  which,  whilst  they  might  be  helpful  and  interesting,  are  in  no 
sense  necessary. 

For  this  reason  the  determination  of  the  water,  the  total  solids  and  the  milk  sugar  is 
not  required  as  a  part  of  the  routine  examination. 

1  Should  it  be  deemed  desirable  and  necessary  to  conduct  tests  for  sediment,  the 
presence  of  special  bacteria,  or  the  number  of  leucocytes  the  methods  adopted  by  the 
committee  of  the  American  Public  Health  Association  should  be  followed. 


416  CITY  MILK  SUPPLY 

70.  The  chemical  analyses  shall  be  made  by  a  competent  chemist  designated  by 
the  medical  milk  commission. 

71.  Method  of  Obtaining  Samples. — The  samples  to  be  examined  by  the  chemist 
shall  have  been  examined  previously  by  the  bacteriologist  designated  by  the  medical 
milk  commission,  as  to  temperature,  odor,  taste,  and  bacterial  content. 

72.  Fat  Standards. — The  fat  standard  for  certified  milk  shall  be  4  per  cent.,  with  a 
permissible  range  of  variation  of  from  3.5  to  4.5  per  cent. 

73.  The  fat  standard  for  certified  cream  shall  be  not  less  than  18  per  cent. 

74.  If  it  is  desired  to  sell  higher  fat-percentage  milks  or  creams  as  certified 
milks  or  creams,  the  range  of  variation  for  such  milks  shall  be  0.5  per  cent,  on 
either  side  of  the  advertised  percentage  and  the  range  of  variations  for  such  creams 
shall  be  2  per  cent,  on  either  side  of  the  advertised  percentage. 

75.  The  fat  content  of  certified  milks  and  creams  shall  be  determined  at  least 
once  each  month. 

76.  The  methods  recommended  for  this  purpose  are  the  Babcock  (a),  the 
Leffmann-Beam  (6),  and  the  Gerber  (c). 

(a)  Babcock  test. — The  Babcock  test  is  based  on  the  fact  that  strong  sulphuric  acid 
will  dissolve  the  non-fatty  solid  constituents  of  milk,  and  thus  enable  the  fat  to  sepa- 
rate on  standing.  It  can  be  conducted  by  any  of  the  Babcock  outfits  which  are  pur- 
chasable in  the  market. 

"The  test  is  made  by  placing  in  the  special  test  bottle  18  grams  (17.6  c.c.)  of  milk. 
To  this  is  added,  from  a  pipette,  burette,  or  measuring  bottle,  17.5  c.c.  commercial 
sulphuric  acid  of  a  specific  gravity  of  1.82  to  1.83.  The  contents  of  the  bottle  are 
carefully  and  thoroughly  mixed  by  a  rotary  motion.  The  mixture  becomes  brown 
and  heat  is  generated.  The  test  bottle  is  now  placed  in  a  properly  balanced  centrifuge 
and  whirled  for  5  min.  at  a  speed  of  from  800  to  1,200  revolutions  per  min.  Hot 
water  is  then  added  to  fill  the  bottle  to  the  lower  part  of  the  neck,  after  which  it  is 
again  whirled  for  two  minutes.  Now,  enough  hot  water  is  added  to  float  the  column 
of  fat  into  the  graduated  portion  of  the  neck  of  the  bottle,  and  the  whirling  is  repeated 
for  a  minute.  The  amount  of  fat  is  read  while  the  neck  of  the  bottle  is  still  hot.  The 
reading  is  from  the  upper  limits  of  the  meniscus.  A  pair  of  calipers  is  of  assistance  in 
measuring  the  column  of  fat."  (Jensen's  "Milk  Hygiene,"  Leonard  Pearson's  trans- 
lation.) 

(6)  Leffman-Beam  test. — The  distinctive  feature  is  the  use  of  fusel  oil,  the  effect 
of  which  is  to  produce  a  greater  difference  in  surface  tension  between  the  fat  and  the 
liquid  in  which  it  is  suspended,  and  thus  promote  its  readier  separation.  This  effect 
has  been  found  to  be  heightened  by  the  presence  of  a  small  amount  of  hydrochloric 
acid. 

The  test  bottles  have  a  capacity  of  about  30  c.c.  and  are  provided  with  a  graduated 
neck,  each  division  of  which  represents  9.1  per  cent,  by  weight  of  butter  fat. 

Fifteen  centimeters  of  the  milk  are  measured  into  the  bottle,  3  c.c.  of  a  mixture  of 
equal  parts  of  amyl  alcohol  and  strong  hydrochloric  acid  added  and  mixed.  Then  9 
c.c.  of  concentrated  sulphuric  acid  is  added  in  portions  of  about  1  c.c.;  after  each 
addition  the  liquids  are  mixed  by  giving  the  bottle  a  gyratory  motion.  If  the  fluid 
has  not  lost  all  of  its  milky  color  by  this  treatment,  a  little  more  concentrated  acid 
must  be  added.  The  neck  of  the  bottle  is  now  immediately  filled  at  about  the  zero 
point  with  one  part  sulphuric  acid  and  two  parts  water,  well  mixed  just  before  using. 
Both  the  liquid  in  the  bottle  and  the  diluted  acid  must  be  hot.  The  bottle  is  then 
placed  at  once  in  the  centrifugal  machine;  after  rotation  from  one  to  two  minutes, 
the  fat  will  collect  in  the  neck  of  the  bottle  and  the  percentage  may  be  read  off. 

(c)  Gerber' s  test. — This  test  is  applied  as  follows :  The  test  bottles  are  put  into  the 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  417 

stand  with  the  mouths  uppermost;  then,  with  the  pipette  designed  for  the  purpose, 
or  with  an  automatic  measurer,  10  c.c.  of  sulphuric  acid  are  filled  into  the  test  bottle, 
care  being  taken  not  to  allow  any  to  come  in  contact  with  the  neck.  The  few  drops 
remaining  in  the  tip  of  the  pipette  should  not  be  blown  out.  Then  11  c.c.  of  milk 
are  measured  with  the  proper  pipette  and  allowed  to  flow  slowly  onto  the  acid,  so  that 
the  two  liquids  mix  as  little  as  possible.  Finally,  the  amyl  alcohol  is  added.  (It  is 
important  to  use  the  reagents  in  the  proper  order,  which  is — sulphuric  acid,  milk, 
amyl  alcohol.  If  the  sulphuric  acid  is  followed  by  amyl  alcohol  and  the  milk  last, 
then  the  result  is  sometimes  incorrect.)  A  rubber  stopper,  which  must  not  be  dam- 
aged, is  then  fitted  into  the  mouth  of  the  test  bottle,  and  the  contents  are  well  shaken, 
the  thumb  being  kept  on  the  stopper  to  prevent  it  coming  out.  As  a  considerable 
amount  of  heat  is  generated  by  the  action  of  the  sulphuric  acid  on  the  milk,  the  test 
bottle  should  be  wrapped  in  a  cloth. 

The  shaking  of  the  sample  must  be  done  thoroughly  and  quickly,  and  the  test  bottle 
inverted  several  times,  so  that  the  liquid  in  the  neck  becomes  thoroughly  mixed.  By 
pressing  in  the  rubber  stopper  the  height  of  the  liquid  can  be  brought  to  about  the 
zero  point  on  the  scale. 

If  only  a  few  samples  have  to  be  analyzed  and  the  room  is  warm,  the  test  bottles 
can  be  put  into  the  centrifuge  without  any  preliminary  heating,  otherwise  the  test 
bottles  must  be  warmed  for  a  few  minutes  (not  longer)  in  the  water  bath  at  a  tempera- 
ture of  60°  to  65°C.  When  the  temperature  rises  higher  than  this,  say  above  70°C., 
the  rubber  stopper  is  liable  to  be  blown  out  of  the  test  bottle.  After  the  test  bottles 
have  been  heated  they  are  arranged  symmetrically  in  the  centrifuge  and  whirled  for 
3  to  4  min.  at  a  speed  of  about  1,000  revolutions  per  min.  When  the  centrifuge  has 
a  heating  arrangement  attached  to  it,  the  preliminary  warming  is  not,  of  course, 
necessary.  When  the  test  bottles  are  taken  out  of  the  centrifuge,  they  are  again  placed 
in  the  water  bath  at  a  temperature  of  60°  to  65°C.,  and  left  there  for  several  minutes 
before  being  read;  where  the  centrifuge  is  heated,  the  tubes  can  be  read  off  as  taken 
from  the  centrifuge. 

By  carefully  screwing  in  the  rubber  stopper,  or  even  by  pressing  it,  the  lower  limit 
of  the  fat  column  is  brought  onto  one  of  the  main  divisions  of  the  scale,  and  then, 
by  holding  the  test  bottle  against  the  light  the  height  of  the  column  of  fat  can  be 
accurately  ascertained.  The  lowest  point  of  the  meniscus  is  taken  as  the  level  when 
reading  the  upper  surface  of  the  fat  in  a  sample  of  .whole  milk,  and  the  middle  of  the 
meniscus  for  separated  milk. 

If  the  column  of  fat  is  not  clear  and  sharply  defined,  the  sample  must  be  again 
whirled  in  the  centrifuge. 

Each  division  on  the  scale  is  equivalent  to  0.1  per  cent.,  so  it  is  very  easy  to  read  to 
0.05  per  cent.,  or,  with  a  lens,  to  0.025  per  cent.  If  the  number  which  is  read  off  is 
multiplied  by  0.1,  then  the  percentage  quantity  of  fat  in  the  milk  is  obtained;  e.g., 
if  the  number  on  the  scale  was  36.5,  then  the  percentage  of  fat  is  3.65.  (Milk  and 
Dairy  Products,"  Barthel;  translated  by  Goodwin,  p.  71.) 

77.  Before  condemning  samples  of  milk  which  have  fallen  outside  the  limits 
allowed,  the  chemist  shall  have  determined,  by  control  ether  extractions,  that 
his  apparatus  and  his  technique  are  reliable. 

78.  Protein  Standard. — The  protein  standard  for  certified  milk  shall  be  3.50 
per  cent,  with  a  permissible  range  of  variation  of  from  3  to  4  per  cent. 

79.  The  protein  standard  for  certified  cream  shall  correspond  to  the  protein 
standard  for  certified  milk. 

80.  The  protein  content  shall  be  determined  only  when  any  special  considera- 
tion seems  to  the  medical  milk  commission  to  make  it  desirable. 

27 


418  CITY  MILK  SUPPLY 

81.  It  shall  be  determined  by  the  Kjeldahl  method,  using  the  Gunning  or 
some  other  reliable  modification,  and  employing  the  factor  6.25  in  reckoning  the 
protein  from  the  nitrogen. 

Kjeldahl  Method. — Five  cubic  centimeters  of  milk  are  measured  carefully  into  a 
flat-bottom  800-c.c.  Jena  flask,  20  c.c.  of  concentrated  sulphuric  acid  (C.  P.;  sp.  gr., 
1.84)  are  added,  and  0.7  gram  of  mercuric  oxid  (or  its  equivalent  in  metallic  mercury); 
the  mixture  is  then  heated  over  direct  flame  until  it  is  straw-colored  or  perfectly 
white;  a  few  crystals  of  potassium  permanganate  are  now  added  till  the  color  of  the 
liquid  remains  green.  All  the  nitrogen  in  the  milk  has  then  been  converted  into 
the  form  of  ammonium  sulphate.  After  cooling,  200  c.c.  of  ammonia-free  distilled 
water  are  added,  20  c.c.  of  a  solution  of  potassium  sulphide  (containing  40  grams 
sulphide  per  liter),  and  a  fraction  of  a  gram  of  powdered  zinc.  A  quantity  of  semi- 
normal  HC1  solution  more  than  sufficient  to  neutralize  the  ammonia  obtained  in 
the  oxidation  of  the  milk  is  now  carefully  measured  out  from  a  delicate  burette 
(divided  into  Ko  c.c.)  into  an  Erlenmeyer  flask  and  the  flask  connected  with  a  dis- 
tillation apparatus.  At  the  other  end  the  Jena  flask  containing  the  watery  solution 
of  the  ammonium  sulphate  is  connected,  after  adding  50  c.c.  of  a  concentrated  soda 
solution  (1  Ib.  "pure  potash"  dissolved  in  500  c.c.  of  distilled  water  and  allowed 
to  settle) ;  the  contents  of  the  Jena  flask  are  now  heated  to  boiling,  and  the  distillation 
is  continued  for  40  min.  to  an  hour,  until  all  ammonia  has  been  distilled  over. 

The  excess  of  acid  in  the  Erlenmeyer  receiving  flask  is  then  accurately  titrated 
back  by  means  of  a  tenth-normal  standard  ammonia  solution,  using  a  cochineal  solu- 
tion as  an  indicator.  From  the  amount  of  acid  used  the  per  cent,  of  nitrogen  is  ob- 
tained; and  from  it  the  per  cent,  of  casein  and  albumen  in  the  milk  by  multiplying 
by  6.25.  The  amount  of  nitrogen  contained  in  the  chemicals  used  is  determined  by 
blank  experiments  and  deducted  from  the  nitrogen  obtained  as  described.  (Farring- 
ton  and  Woll,  "Testing  Milk  and  Its  Products,"  p.  221.) 

82.  Coloring  Matter  and  Preservatives. — All  certified  milks  and  creams  shall 
be  free  from  adulteration,  and  coloring  matter  and  preservatives  shall  not  be 
added  thereto. 

83.  Tests  for  the  detection  of  added  coloring  matter  shall  be  applied  when- 
ever the  color  of  the  milk  or  cream  is  such  as  to  arouse  suspicion. 

Test  for  Coloring  Matter. — The  presence  of  foreign  coloring  matter  in  milk  is  easily 
shown  by  shaking  10  c.c.  of  the  milk  with  an  equal  quantity  of  ether;  on  standing, 
a  clear  ether  solution  will  rise  to  the  surface;  if  artificial  coloring  matter  has  been  added 
to  the  milk,  the  solution  will  be  yellow  colored,  the  intensity  of  the  color  indicating 
the  quantity  added;  natural  fresh  milk  will  give  a  colorless  ether  solution.  ("Testing 
Milk  and  Its  Products,"  Farrington  and  Woll,  p.  244.) 

84.  Tests  for  the  detection  of  formaldehyde,  borax,  and  boracic  acid  shall 
be  applied  at  least  once  in  each  month.     Occasionally  application  of  tests  for 
the   detection   of   salicylic   acid,   benzoic   acid,   and   the   benzoates   are   also 
recommended. 

Test  for  the  Detection  of  Formaldehyde. — Five  cubic  centimeters  of  milk  is  measured 
into  a  white  porcelain  dish,  and  a  similar  quantity  of  water  added;  10  c.c.  of  HC1, 
containing  a  trace  of  Fe2Cl6  is  added,  and  the  mixture  is  heated  very  slowly.  If 
formaldehyde  is  present,  a  violet  color  will  be  formed.  ("Testing  Milk  and  Its 
Products,"  Farrington  and  Woll,  p.  249.) 

Test  for  Boracic  Acid  (Borax,  Borates,  Preservaline,  etc.). — One  hundred  cubic  centi- 
meters of  milk  are  made  alkaline  with  a  soda  or  potash  solution,  and  then  evaporated 


CONTROL  OF   THE  PUBLIC  MILK  SUPPLY  419 

to  dryness  and  incinerated.  The  ash  is  dissolved  in  water,  to  which  a  little  hydro- 
chloric acid  has  been  added,  and  the  solution  filtered.  A  strip  of  turmeric  paper  mois- 
tened with  the  filtrate  will  be  colored  reddish  brown  when  dried  at  100°C.  on  a  watch 
glass,  if  boracic  acid  is  present. 

If  a  little  alcohol  is  poured  over  the  ash  to  which  concentrated  sulphuric  acid  has 
been  added,  and  fire  is  set  to  the  alcohol,  after  a  little  while  this  will  burn  with  a 
yellowish-green  tint,  especially  noticeable  if  the  ash  is  stirred  with  a  glass  rod  and 
when  the  flame  is  about  to  go  out.  ("  Testing  Milk  and  Its  Products,"  Farrington  and 
Woll,  p.  247.) 

Test  for  Salicylic  Acid  (Salicylates,  etc.}. — Twenty  cubic  centimeters  of  milk  are  acid- 
ulated with  sulphuric  acid  and  shaken  with  ether;  the  ether  solution  is  evaporated, 
and  the  residue  treated  with  alcohol  and  a  little  iron-chlorid  solution;  a  deep  violet 
color  will  be  obtained  in  the  presence  of  salicylic  acid.  ("Testing  Milk  and  Its  Prod- 
ucts," Farrington  and  Woll,  p.  248.) 

Test  for  Benzole  Acid. — Two  hundred  and  fifty  to  five  hundred  cubic  centimeters  of 
milk  are  made  alkaline  with  a  few  drops  of  lime  or  baryta  water,  and  then  evaporated 
to  about  a  quarter  of  the  bulk.  Powdered  gypsum  is  stirred  into  the  remaining  liquid 
until  a  paste  is  formed,  when  is  then  dried  on  the  water  bath.  The  gypsum  only 
serves  to  hasten  the  drying,  and  powdered  pumice  stone  or  sand  can  be  used  equally 
well.  When  the  mass  is  dry,  it  is  finely  powdered  and  moistened  with  dilute  sul- 
phuric acid  and  shaken  out  three  or  four  times  with  about  twice  the  volume  of  50  per 
cent,  alcohol,  in  which  benzoic  acid  is  easily  soluble  in  the  cold,  the  fat  only  being  dis- 
solved to  a  very  slight  extent  or  not  at  all.  The  acid  alcoholic  liquid  from  the  various 
extractions,  which  contains  milk  sugar  and  inorganic  salts  in  addition  to  the  benzoic 
acid,  is  neutralized  with  baryta  water  and  evaporated  to  a  small  bulk.  Dilute  sul- 
phuric acid  is  again  added,  and  the  liquid  shaken  out  with  small  quantities  of  ether. 
On  evaporation  of  the  ether,  the  benzoic  acid  is  left  behind  in  almost  pure  state,  the 
only  impurities  being  small  quantities  of  fat  or  ash. 

The  benzoic  acid  which  is  obtained  is  dissolved  in  a  small  quantity  of  warm  water, 
a  drop  of  sodium  acetate  and  neutral  ferric  chloride  added,  and  the  red  precipitate  of 
benzoate  of  iron  indicates  the  presence  of  the  acid.  ("Milk  and  Dairy  Products," 
Barthel,  translated  by  Goodwin,  p.  121.) 

85.  Detection  of  Heated  Milk. — Certified  milk  or  cream  shall  not  be  subjected 
to  heat  unless  specially  directed  by  the  commission  to  meet  emergencies. 

86.  Tests  to  determine  whether  such  milks  and  creams  have  been  subjected 
to  heat  shall  be  applied  at  least  once  each  month. 

Detection  of  Heated  Milk — Storch's  Method. — Five  cubic  centimeters  of  milk  are 
poured  into  a  test  tube;  a  drop  of  weak  solution  of  hydrogen  dioxide  (about  0.2  per 
cent.)  which  contains  about  0.1  per  cent,  sulphuric  acid,  is  added,  and  two  drops  of  a 
2  per  cent,  solution  of  paraphenylendiamin  (solution  should  be  renewed  quite  often), 
then  the  fluid  is  shaken.  If  the  milk  or  the  cream  becomes,  at  once,  indigo  blue,  or  the 
whey  violet  or  reddish  brown,  then  this  has  not  been  heated  or,  at  all  events,  it  has  not 
been  heated  higher  than  78°C.  (172.5°F.);  if  the  milk  becomes  a  light  bluish  gray  im- 
mediately or  in  the  course  of  half  a  minute,  then  it  has  been  heated  to  79°  to  80°C. 
(174.2°  to  176°F.).  If  the  color  remains  white,  the  milk  has  been  heated  at  least  to 
80°C.  (176°F.).  In  the  examination  of  sour  milk  or  sour  buttermilk,  lime  water  must 
be  added,  as  the  color  reaction  is  not  shown  in  acid  solution. 

Arnold's  Guaiac  Method. — A  little  milk  is  poured  into  a  test  tube  and  a  little  tincture 
of  guaiac  is  added,  drop  by  drop.  If  the  milk  has  not  been  heated  to  80°C.  (176°F.) 
a  blue  zone  is  formed  between  the  two  fluids:  heated  milk  gives  no  reaction,  but 
remains  white.  The  guaiac  tincture  should  not  be  used  perfectly  fresh,  but  should 


420  CITY  MILK  SUPPLY 

have  stood  a  few  days  and  its  potency  have  been  determined.  Thereafter  it  can  be 
used  indefinitely.  These  tests  for  heated  milk  are  only  active  in  the  case  of  milks 
which  have  been  heated  to  176°F.  or  80°C.  (Jensen's  "Milk  Hygiene,"  Pearson's 
translation,  p.  192.) 

Microscopic  Test  for  Heated  (pasteurized)  Milk — Frost  and  Ravenel. — About  15  c.c. 
of  milk  are  centrifuged  for  5  min.,  or  long  enough  to  throw  down  the  leucocytes. 
The  cream  layer  is  then  completely  removed  with  absorbent  cotton  and  the  milk  drawn 
off  with  a  pipette,  or  a  fine-pointed  tube  attached  to  a  Chapman  air  pump.  Only 
about  2  mm.  of  milk  are  left  above  the  sediment  which  is  in  the  bottom  of  the  sedi- 
mentation tube. 

The  stain,  which  is  an  aqueous  solution  of  safranin  0,  soluble  in  water,  is  then 
added  very  slowly  from  an  opsonizing  pipette.  The  important  thing  is  to  mix  stain 
and  milk  so  slowly  that  clotting  does  not  take  place.  The  stain  is  added  until  a  deep 
opaque  rose  color  is  obtained.  After  standing  3  min.,  by  means  of  the  opson- 
izing pipette,  which  has  been  washed  out  in  hot  water,  the  stained  sediment  is  then 
transferred  to  slides.  A  small  drop  is  placed  at  the  end  of  each  of  several  slides  and 
spread  by  means  of  a  glass  spreader,  as  in  Wright's  method  of  opsonic  index  determi- 
nations (see  author's  note  at  end  of  the  methods). 

In  an  unheated  milk  the  polymorphonuclear  leucocytes  have  their  protoplasm 
slightly  tinged  or  are  unstained. 

In  heated  milk  the  polymorphonuclear  leucocytes  have  their  nuclei  stained.  In 
milk  heated  to  63°C.  or  above,  practically  all  of  the  leucocytes  have  their  nuclei 
definitely  stained.  When  milk  is  heated  at  a  lower  temperature  the  nuclei  are  not 
all  stained  above  60°C.  The  majority,  however,  are  stained. 

87.  Specific  Gravity. — The  specific  gravity  of  certified  milk  shall  range  from 
1.029  to  1.034. 

88.  The  specific  gravity  shall  be  determined  at  least  each  month. 

The  Quevenne  lactodensimeter  is  recommended  for  the  determination  of  the  spe- 
cific gravity.  It  is  made  like  an  ordinary  aerometer  and  divided  into  degrees  which 
correspond  to  a  specific  gravity  from  1.014  to  1.040,  or  only  from  1.022  to  1.038, 
since,  by  the  latter  division,  a  greater  space  is  gained  between  the  different  degrees 
without  unduly  lengthening  the  instrument.  From  such  a  lactodensimeter  one  can 
easily  read  of?  four  decimal  places. 

The  milk  the  specific  gravity  of  which  is  to  be  determined  is  well  shaken  and  poured 
into  a  high  glass  cylinder  of  suitable  diameter;  the  aerometer  is  dropped  in  slowly, 
in  order  to  prevent  its  bobbing  up  and  down.  (The  bulb  should  be  free  from  adhering 
air  bubbles.)  The  figures  on  the  stem  are  the  second  and  third  decimals  of  the  num- 
bers of  the  specific  gravity,  so  that  34  is  to  be  read  1.034.  For  this  examination,  the 
temperature  of  the  milk  must  be  15°C.  (60°F.);  if  it  is  not,  the  specific  gravity  of  the 
milk  at  15°C.  must  be  calculated  from  the  specific  gravity  found  and  from  the  tempera- 
ture, for  in  milk  inspection  and  analysis  this  is  the  standard. 

METHODS  AND  REGULATIONS  FOR  THE  MEDICAL  EXAMINATION  OF  EMPLOYEES, 
THEIR  HEALTH  AND  PERSONAL  HYGIENE 

89.  A  medical  officer,  known  as  the  attending  dairy  physician,  shall  be  selected 
by  the  commission  who  should  reside  near  the  dairy  producing  certified  milk. 
He  shall  be  a  physician  in  good  standing  and  authorized  by  law  to  practice  medi- 
cine; he  shall  be  responsible  to  the  commission  and  subject  to  its  direction.     In 
case  more  than  one  dairy  is  under  the  control  of  the  commission  and  they  are  in 
different  localities,  a  separate  physician  should  be  designated  for  employment 
for  the  supervision  of  each  dairy. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  421 

90.  Before  any  person  shall  come  on  the  premises  to  live  and  remain  as  an 
employee,  such  person,  before  being  engaged  in  milking  or  the  handling  of  milk, 
shall  be  subjected  to  a  complete  physical  examination  by  the  attending  physician. 
No  person  shall  be  employed  who  has  not  been  vaccinated  recently  or  who  upon 
examination  is  found  to  have  a  sore  throat,  or  to  be  suffering  from  any  form  of 
tuberculosis,  venereal  disease,  conjunctivitis,  diarrhea,  dysentery,  or  who  has  re- 
cently had  typhoid  fever  or  is  proved  to  be  a  typhoid  carrier,  or  who  has  any 
inflammatory  disease  of  the  respiratory  tract,  or  any  suppurative  process  or  in- 
fectious skin  eruption,  or  any  disease  of  an  infectious  or  contagious  nature,  or 
who  has  recently  been  associated  with  children  sick  with  contagious  disease. 

91.  In  addition  to  ordinary  habits  of  personal  cleanliness  all  milkers  shall  have 
well-trimmed  hair,  wear  close-fitting  caps,  and  have  clean-shaven  faces. 

92.  When  the  milkers  live  upon  the  premises  their  dormitories  shall  be  con- 
structed and  operated  according  to  plans  approved  by  the  commission.     A  sepa- 
rate bed  shall  be  provided  for  each  milker  and  each  bed  shall  be  kept  supplied, 
with  clean  bedclothes.     Proper  bathing  facilities  shall  be  provided  for  all  employ- 
ees on  the  dairy  premises,  preferably  a  shower  bath,  and  frequent  bathing  shall 
be  enjoined. 

93.  In  case  the  employees  live  on  the  dairy  premises  a  suitable  building  shall 
be  provided  to  be  used  for  the  isolation  and  quarantine  of  persons  under  suspicion 
of  having  a  contagious  disease. 

The  following  plan  of  construction  is  recommended : 

The  quarantine  building  and  hospital  should  be  one  story  high  and  contain  at  least 
two  rooms,  each  with  a  capacity  of  about  6,000  cu.  ft.  and  containing  not  more 
than  three  beds  each,  the  rooms  to  be  separated  by  a  closed  partition.  The  doors 
opening  into  the  rooms  should  be  on  opposite  sides  of  the  building  and  provided  with 
locks.  The  windows  should  be  barred  and  the  sash  should  be  at  least  5  ft.  from  the 
ground  and  constructed  for  proper  ventilation.  The  walls  should  be  of  a  material 
which  will  allow  proper  disinfection.  The  floor  should  be  of  painted  or  washable 
wood,  preferably  of  concrete,  and  so  constructed  that  the  floor  may  be  flushed  and 
properly  disinfected.  Proper  heating,  lighting,  and  ventilating  facilities  should  be 
provided. 

94.  In  the  event  of  any  illness  of  a  suspicious  nature  the  attending  physician 
shall  immediately  quarantine  the  suspect,  notify  the  health  authorities  and  the 
secretary  of  the  commission,  and  examine  each  member  of  the  dairy  force,  and 
in  every  inflammatory  affection  of  the  nose  or  throat  occurring  among  the  employ- 
ees of  the  dairy,  in  addition  to  carrying  out  the  above-mentioned  program,  the 
attending  physician  shall  take  a  culture  and  have  it  examined  at  once  by  a  com- 
petent bacteriologist  approved  by  the  commission.     Pending  such  examination, 
the  affected  employee  or  employees  shall  be  quarantined. 

95.  It  shall  be  the  duty  of  the  secretary,  on  receiving  notice  of  any  suspicious 
or  contagious  disease  at  the  dairy,  at  once  to  notify  the  committee  having  in 
charge  the  medical  supervision  of  employees  of  the  dairy  farm  upon  which  such 
disease  has  developed.     On  receipt  of  the  notice  this  committee  shall  assume 
charge  of  the  matter,  and  shall  have  power  to  act  for  the  commission  as  its  judg- 
ment dictates.     As  soon  as  possible  thereafter,  the  committee  shall  notify  the 
commission,  through  its  secretary,  that  a  special  meeting  may  be  called  for  ulti- 
mate consideration  and  action. 


422  CITY  MILK  SUPPLY 

96.  When  a  case  of  contagious  disease  is  found  among  the  employees  of  a 
dairy  producing  certified  milk  under  the  control  of  a  medical  milk  commission, 
such  employee  shall  be  at  once  quarantined  and  as  soon  as  possible  removed  from 
the  plant,  and  the  premises  fumigated. 

When  a  case  of  contagion  is  found  on  a  certified  dairy  it  is  advised  that  a  printed 
notice  of  the  facts  shall  be  sent  to  every  householder  using  the  milk,  giving  in  detail 
the  precautions  taken  by  the  dairyman  under  the  direction  of  the  commission,  and 
it  is  further  advised  that  all  milk  produced  at  such  dairy  shall  be  heated  at  145°F. 
for  40  min.  or  155°F.  for  30  min.,  or  167°F.  for  20  min.,  and  immediately  cooled  to 
50°F.  These  facts  should  also  be  part  of  the  notice,  and  such  heating  of  the  milk 
should  be  continued  during  the  accepted  period  of  incubation  for  such  contagious 
disease. 

The  following  method  of  fumigation  is  recommended : 

After  all  windows  and  doors  are  closed  and  the  cracks  sealed  by  strips  of  paper 
applied  with  flour  paste,  and  the  various  articles  in  the  room  so  hung  or  placed  as  to 
be  exposed  on  all  sides,  preparations  should  be  made  to  generate  formaldehyde  gas  by 
the  use  of  20  oz.  of  formaldehyde  and  10  oz.  of  permanganate  of  potash  for  every 
1,000  cu.  ft.  of  space  to  be  disinfected. 

For  mixing  the  formaldehyde  and  potassium  permanganate  a  large  galvanized-iron 
pail  or  cylinder  holding  at  least  20  quarts  and  having  a  flared  top  should  be  used  for 
mixing  therein  20  oz.  of  formaldehyde  and  10  oz.  of  permanganate.  A  cylinder 
at  least  5  ft.  high  is  suggested.  The  containers  should  be  placed  about  in  the  rooms 
and  the  necessary  quantity  of  permanganate  weighed  and  placed  in  them.  The 
formaldehyde  solution  for  each  pail  should  then  be  measured  into  a  widemouthed 
cup  and  placed  by  the  pail  in  which  it  is  to  be  used. 

Although  the  reaction  takes  place  quickly,  by  making  preparations  as  advised  all 
of  the  pails  can  be  "set  off"  promptly  by  one  person,  since  there  is  nothing  to  do  but 
pour  the  formaldehyde  solution  over  the  permanganate.  The  rooms  should  be  kept 
closed  for  4  hr.  As  there  is  a  slight  danger  of  fire,  the  reaction  should  be 
watched  through  a  window  or  the  pails  placed  on  a  non-inflammable  surface. 

97.  Following  a  weekly  medical  inspection  of  the  employees,  a  monthly 
report  shall  be  submitted  to  the  secretary  of  the  medical  milk  commission,  on  the 
same  recurring  date  by  the  examining  visiting  physician. 

The  following  schedule,  filled  out  in  writing  and  signed  by  himself,  is  recommended 
as  a  suitable  form  for  the  attending  physician's  report : 

This  is  to  certify  that,  on  the  dates  below  indicated,  official  visits  were  made  to  the 

dairy,  owned  and  conducted  by  —  —  of  —  —  (indicating  town  and  State), 

where  careful  inspections  of  the  dairy  employees  were  made. 

(a)  Number  and  dates  of  visits  since  last  report.  — . 

(g)  Number  of  men  employed  on  the  plant.  — . 

(c)  Has  a  recent  epidemic  of  contagion  occurred  near  the  dairy,  and  what  was  its 
nature  and  extent?     . 

(d)  Have  any  cases  of  contagious  or  infectious  disease  occurred  among  the  men 
since  the  last  report?    . 


(e)  Disposition  of  such  cases.     . 

(/)  What  individual  sickness  has  occurred  among  the  men  since  the  last  report? 

(0)  Disposition  of  such  cases.     . 

(h)  Number  of  employees  now  quarantined  for  sickness.  — . 

(i}  Describe  the  personal  hygiene  of  the  men  employed  for  milking  when  prepared 
for  and  during  the  process  of  milking.     . 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  423 

(i)  What  facilities  are  provided  for  sickness  in  employees?     . 

(fc)  General  hygienic  condition  of  the  dormitories  or  houses  of  the  employees. 


(0  Suggestions  for  improvement 


\1>J      UUg£COl>.HJl.lQ    J.VJ1    UU£f*W  VVAUWIH.  . 

(m)  What  is  the  hygienic  condition  of  the  employees  and  their  surroundings? 


(ft)  How  many  employees  were  examined  at  each  of  the  foregoing  visits? 
(o)  Remarks.     . 


Attending  physician. 
Date, . 

NOTE. — Since  these  methods  and  standards  were  adopted  the  standard  methods 
of  bacteriological  analysis  of  the  American  Public  Health  Association  quoted  in 
paragraph  65  have  been  superseded  by  the  methods  adopted  in  1916.  Also,  Frost 
has  modified  the  microscopic  test  for  heated  milk  given  in  paragraph  86.  (Author.) 

Enforcement  of  the  Milk  Code. — Having  adopted  an  ordinance,  the 
next  thing  is  to  enforce  it.  This  duty  in  most  municipalities  devolves 
upon  the  health  officer.  In  small  cities  he  actually  does  the  inspection 
and  analytical  work  but  in  the  larger  ones  it  is  done  under  his  direction 
through  a  bureau  of 'milk  control  whose  chief  is  very  largely  responsible 
for  the  success  of  the  service.  Those  who  formulate  the  policy  to  be 
adopted  in  improving  the  milk  supply  should  recognize  that  in  its  last 
analysis  the  milk  question  is  a  financial  problem.  An  inexorable  con- 
dition of  dairy  farmers  and  milk  contractors  remaining  in  business  is 
that  they  shall  make  money,  therefore  any  attempt  to  impose  on  the  milk 
business  such  conditions  that  it  becomes  unprofitable  results  either  in 
the  failure  of  the  proposed  regulatory  measures  with  consequent  confusion 
of  their  proponents  or  in  forcing  good  milkmen  out  of  business  which,  of 
the  two  results,  is  least  likely  to  occur.  Not  only  do  pecuniary  considera- 
tions rule  the  producers  and  distributors  but  the  efforts  at  control  are 
directly  limited  by  the  amount  of  money  available  for  the  work.  The 
amount  expended  by  American  cities  in  suspervising  their  milk  supplies 
is  not  large.  Kelly  of  the  Dairy  Division  of  the  U.  S.  Department  of 
Agriculture  in  1913  found  that  of  162  cities,  22  spent  absolutely  nothing 
and  in  the  others  the  expenditure  ranged  from  J^Q  ct.  per  capita  per  year 
up  to  19  cts.  per  capita  per  year.  The  average  amount  expended,  in 
cities  spending  anything  at  all,  was  4.14  cts.  per  capita  per  year.  These 
figures  included  all  the  moneys  put  into  farm  and  city  inspections,  labora- 
tory work,  supervisory  and  clerical  work,  etc.  So,  every  aspect  presents 
the  financial  question  in  the  foreground. 

The  Milk  Supply  of  a  City  a  Valuable  Asset. — The  milk  supply  of 
a  community  should  be  recognized  as  one  of  its  important  resources,  as 
an  asset  that  should  not  only  be  protected  but  be  developed  and  increased 
in  value.  None  of  the  large  cities  have  attempted  to  estimate  the  amount 
of  capital  that  is  invested  to  their  benefit  in  the  dairy  farms  and  milk 


424  CITY  MILK  SUPPLY 

companies  that  supply  them.  Yet  logically  this  would  seem  to  be  one 
of  the  very  first  steps  to  take  in  attempting  to  regulate  dairying.  Prob- 
ably one  reason  that  it  is  rarely  done  is  that  funds  are  seldom  available 
to  make  the  necessary  surveys.  Harding  and  Brew  made  the  following 
estimate  of  the  capital  invested  in  supplying  milk  to  Geneva,  N.  Y.,  a 
city  of  12,574  inhabitants.  The  region  is  one  of  intensive  fruit  cultivation 
and  all  of  the  milk  producers  are  engaged  in  mixed  farming. 

Cows  600  at  $80  each $48,000 

Land  with  buildings,  3,000  acres  at  $100 300,000 

Equipment,  3,000  acres  at  $20  per  acre 60,000 

City  distributors 50,000 


Total $458,00 

This  is  a  dairy  capitalization  of  $36.42  per  capita  or  from  the  agricultural 
standpoint  of  $763  per  cow  of  which  the  producer  furnishes  $680  and  the 
retailer  $83.  These  students  conclude  that  the  average  producer  was 
accepting  less  than  6  per  cent,  of  the  capital  invested  and  that  his  financial 
salvation  depends  upon  increasing  the  productivity  of  his  land  to  the 
point  where  it  takes  less  than  5  acres  to  support  a  cow  and  on  increasing 
the  productivity  of  his  cows  to  where  they  will  give  over  2,800  qt.  of 
milk  a  year.  The  largest  retailer  of  milk  in  the  district  had  been  in 
business  8  years  and  had  never  paid  7  per  cent,  on  his  stock.  There  is 
no  way  of  knowing  how  nearly  typical  of  conditions  that  prevail  by  and 
large  throughout  the  dairy  industry  these  figures  from  Geneva  are,  but 
it  is  doubtful  if  conditions  in  general  are  better  so  that  it  is  apparent  that 
the  moderate  profits  yielded  by  the  business  make  it  imperative  to  care- 
fully consider  the  cost  of  conditions  it  is  proposed  to  impose  on  the  in- 
dustry and  to  choose  a  method  of  accomplishing  any  desired  reform  that 
will  be  as  inexpensive  as  possible.  If  the  cost  of  milk  to  the  consumer  did 
not  have  to  be  considered,  conditions  governing  the  production  and  sale 
of  milk  might  be  prescribed  that  would  assure  that  only  milk  of  superior 
quality  was  marketed  but  raising  the  price  of  milk  brings  it  into  compe- 
tition with  foods  that  commonly  are  excluded  because  of  their  cost. 
Moreover  the  wages  and  salaries  of  city  folks  are  fixed  and  a  rise  in  price 
of  a  food  means  that  they  have  to  restrict  its  use  or  perhaps  forego  it 
altogether.  The  problem  is  not  only  how  to  protect  the  public  health 
from  impure  milk  but  how  to  promote  the  well-being  of  the  community 
by  getting  an  abundance  of  milk  at  moderate  price. 

Personnel  of  the  Milk  Inspection  Bureau. — This  can  only  be  done  by 
securing  the  cooperation  of  all  concerned,  the  producer,  the  dealer  and  the 
public.  So,  the  composition  of  the  staff  engaged  in  enforcing  the  milk 
ordinance  is  important.  There  is  much  difference  of  opinion  as  to  what 
this  should  be.  It  is  generally  agreed  that  the  men  should  have  some  sort 
of  preparation  or  education  for  their  work  but  there  are  difficulties  in  the 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  425 

way  of  securing  such  men.  The  two  chief  ones  are  that  salaries  are 
ridiculously  inadequate,  and  that  the  positions  of  inspectors  are  commonly 
regarded  as  the  property  of  political  bosses  to  be  used  in  paying  political 
debts.  Added  to  this  is  the  willingness  of  the  public  to  be  badly  served. 
It  seems  to  believe  that  clothing  a  man  with  public  office  supplies  him 
with  intelligence  and  ability.  It  is  too  stupid  to  see  that  a  $900  salary 
gets  a  $900  man  and  insures  the  work  being  done  in  a  $900  way  and  it 
loves  to  maintain  the  fiction  that  it  is  being  served  by  men  of  superior 
ability  who  toil  for  love  of  the  work  or  of  the  public.  Rarely  does  the 
public  see  that  its  interests  are  as  well  worth  while  committing  to  the 
care  of  well-paid  men  as  those  of  private  interests  are.  Moreover,  the 
readiness  of  the  public  to  criticize  its  officers  and  to  assail  them,  acts  as 
a  further  deterrent  to  men  who  value  their  reputations  accepting  a  public 
job.  Some  cities  have  found  this  attitude  does  not  pay  and  have  enlisted 
the  services  of  most  competent  men  in  the  public  service  and  among  them 
are  some  splendid  milk  inspectors. 

Obviously,  the  bureau  of  milk  inspection  has  to  be  organized  with  as 
good  men  as  the  standards  of  the  community  will  permit  being  em- 
ployed. For  the  positions  of  chemists  and  bacteriologists  men  of  par- 
ticular training  along  these  lines  must  be  secured.  For  the  inspection 
service  men  who  have  been  schooled  in  sanitation,  in  scientific  agricul- 
ture, as  veterinarians  or  those  that  have  had  practical  farm  experience 
are  promising  material  to  choose  from.  Unfortunately,  knowing  how  is 
different  from  the  ability  to  do  and  so  there  are  many  disappointments. 
The  men  who  succeed  are  those  who  are  really  interested  in  the  work  and 
it  not  rarely  turns  out  that  some  who  appear  handicapped  by  lack  of 
special  preparation  make  good.  In  some  offices  it  is  the  rule  to  hire 
only  veterinarians,  or  physicians,  or  agriculturalists,  or  what  not.  In 
the  opinion  of  the  writer  this  is  bad  policy  for  a  well-balanced  force  needs 
men  of  different  training.  In  general  it  has  been  found  that  poor  results 
are  obtained  by  appointing  men  to  the  staff  who  divide  their  time  be- 
tween the  practice  of  their  professions  and  the  work  of  the  bureau.  Their 
position  is  equivocal  and  everybody  knows  it.  If  it  is  desired  to  make 
use  of  such  men  they  should  be  hired  to  do  a  particular  service. 

Necessity  of  Defining  the  General  Policies  Adopted. — In  proceeding 
to  enforce  an  ordinance,  the  first  step  is  to  make  what  is  wanted  plain. 
The  standards  adopted  should  be  clearly  defined  and  they  should  be 
explained  to  producers  and  consumers.  As  the  outset  it  should  be 
decided  whether  a  pasteurized  or  unpasteurized  supply  is  wanted. 
A  reasonably  safe  supply  of  the  latter  type  is  possible  only  in  the  case  of 
towns  and  small  cities  whose  milk  is  produced  by  a  few  dairymen  in  the 
surrounding  country.  Even  the  best  of  such  supplies  will  occasionally 
furnish  milk-borne  epidemics  of  infectious  disease.  The  only  effective 
preventative  of  such  outbreaks  is  carefully  controlled  pasteurization. 


426  CITY  MILK  SUPPLY 

As  the  dairies  multiply  and  are  located  at  greater  distances  from  the 
city  the  opportunities  for  the  milk  to  become  infected  are  increased, 
consequently  pasteurization  under  strict  supervision  becomes  a  necessity. 

The  decision  as  to  pasteurization  determines  the  attitude  to  be  taken 
on  the  question  of  bovine  tuberculosis.  An  unpasteurized  milk  supply 
ought  to  come  from  tuberculin-tested  herds,  otherwise  the  milk  will 
certainly  contain  living  tuberculosis  germs  and  a  number  of  children  or 
young  people  in  early  youth  will  contract  the  disease.  Proper  pasteuri- 
zation gives  a  high  degree  of  protection  against  bovine  tuberculosis 
and  makes  it  possible  to  present  the  campaign  that  must  be  waged  against 
it  to  the  farmers  as  necessary  to  protect  their  herds  from  the  severe  losses 
that  the  disease  inflicts,  rather  than  as  a  public  health  measure.  More 
permanent  results  are  obtained  if  the  dairyman  can  be  brought  to  see 
that  the  movement  to  eradicate  the  disease  is  calculated  to  protect  and 
improve  his  herds  than  are  possible  when  the  movement  seems  to  him  to 
be  an  attempt  to  guard  others,  by  the  sacrifice  of  his  property,  from  a 
disease  whose  very  existence  seems  to  him  mythical. 

Necessity  of  a  General  Survey  of  the  Producing  Territory. — Having 
decided  on  the  general  policies  of  control  to  be  adopted  a  survey  of  the 
dairy  situation  should  be  undertaken.  The  length  of  winter,  the  period 
when  the  cattle  are  closely  confined  in  barns  should  be  determined;  it 
should  be  noted  what  extremes  of  heat  and  cold  the  herds  have  to  endure 
and  at  what  time  these  occur.  The  amount  and  distribution  of  the 
rainfall,  the  prevalence  of  fogs  and  other  weather  conditions  that  may 
affect  the  ventilation  of  the  barns,  the  raising  of  crops  and  the  health  of 
the  herds  should  be  recorded.  The  general  topography  of  the  country 
bears  a  relation  to  the  water  supply,  the  drainage,  the  condition  of  the 
roads  over  which  the  milk  must  be  hauled,  etc. 

The  character  of  the  people  engaged  in  dairying  should  be  studied. 
They  may  be  classified  according  to  their  occupancy  of  the  land,  as  to 
whether  they  are  renters  or  owners  which  often  determines  their  ability 
to  make  improvements  on  the  property  they  occupy.  They  may  be 
grouped  according  to  the  kinds  of  farming  they  practice;  it  is  much  easier 
to  introduce  improvements  in  a  district  where  dairy  farming  is  the 
principal  business  than  ifl  those  where  it  is  incidental  to  grain  growing, 
fruit  growing  or  other  kinds  of  agriculture.  The  farms  that  have  and 
those  that  have  not  proper  dairy  equipment  should  be  noted.  The  social 
development  of  a  farming  community  is  important  for  the  condition  of  its 
schools,  its  habits  of  reading  and  study,  and  its  opportunities  for  recrea- 
tion determine  its  intelligence  and  ability  to  progress.  It  should  be  ob- 
served how  many  farmers  there  are  who  will  welcome  inspection,  how 
many  who  may  be  inspired  to  adopt  better  methods  and  what  proportion, 
because  they  will  not  do  so,  will  have  to  be  eliminated. 

General  market  conditions  should  be  investigated.     It  should  be 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  427 

determined  whether  dairying  has  reached  the  maximum  development 
possible  in  the  district  or  whether  it  may  be  greatly  increased.  Whether 
there  is  but  a  single  market  for  the  milk  or  whether  there  is  competition 
for  it  between  creameries  and  condenseries  or  between  different  cities 
should  be  noted. 

The  breed  and  character  of  the  cows  should  be  observed  and  the  domi- 
nant breeds  in  the  different  herds  recorded  so  that  it  may  be  known 
whether  to  expect  milk  carrying  a  good  percentage  of  milk  solids  or  not 
and  whether  the  need  is  urgent  of  a  campaign  for  better  herds. 

The  water  supply  of  the  different  farms  should  be  examined  and 
its  adequacy,  permanency,  temperature  and  purity  should  be  determined. 
The  temperature  of  the  water  is  important  for  it  tells  to  what  degree  milk 
can  be  cooled  on  the  farm  without  the  use  of  ice. 

The  means  of  transportation  should  be  studied.  The  distance  milk 
is  hauled  to  the  shipping  point  or  to  the  city  should  be  known  and  whether 
it  is  done  in  wagons  or  motor  cars  and  whether  cooperative  hauling  is 
practised. 

An  estimate  should  be  made  as  to  whether  cost  of  producing  milk  is 
reasonable  or  whether  slovenly  diarying  or  conditions  beyond  the  farmers 
control  make  the  cost  of  production  excessive. 

Finally,  the  probable  value  of  the  farmer's  investment  in  the  business 
and  the  condition  of  his  property  should  be  noted,  in  order  to  judge 
whether  or  not  the  price  paid  for  his  milk  is  sufficient  to  make  it  worth 
his  while  put  in  still  more  capital  and  to  adopt  better  methods  of  dairying. 

Such  observations  as  these  ought  to  furnish  information  that  will 
enable  the  health  officer  to  organize  a  constructive  farm-inspection 
policy  but  before  any  regular  inspection  or  analytical  work  is  started  a 
system  of  keeping  office  records  should  be  devised. 

Office  Records. — The  importance  of  this  can  hardly  be  overstated  for 
if  an  office  is  successful  in  winning  the  confidence  of  the  public,  questions 
are  constantly  asked  that  can  be  properly  answered  only  by  reference 
to  the  records.  Therefore,  they  should  be  adequate  and  in  a  permanent, 
convenient,  usable  form.  There  should  be  a  system  of  filing  correspond- 
ence, score  cards  and  complaints.  Blank  forms  should  be  adopted  for 
licenses,  labeling  samples,  recording  analyses,  sending  out  notices,  etc. 
A  map  should  be  available  showing  the  location  of  the  divers  farms  that 
send  milk  to  the  city.  Each  of  these  farms  should  be  given  a  number 
which  should  appear  on  all  records  pertaining  to  the  farm.  In  like  mari- 
ner there  should  be  a  city  map  showing  the  places  where  milk  is 
sold  and  these  places,  too,  should  be  numbered.  With  a  good  record 
system  established  the  general  work  of  the  bureau  may  be  laid  out. 

Important  Phases  of  Milk  Control. — Regulation  and  improvement  of 
the  milk  supply  is  accomplished  by  inspection,  at  frequent  stages  of  its 
long  journey  from  the  cow  to  the  consumer,  of  the  milk  and  of  the  methods 


428  CITY  MILK  SUPPLY 

employed  in  handling  it,  by  teaching  the  consumer  how  to  care  for  milk 
and  its  value  as  food,  by  chemical  and  bacteriological  control  of  the 
supply,  by  developing  a  scheme  for  detecting  the  presence  of  milk-borne 
contagion  and  for  checking  its  spread,  and  finally  by  stimulating  general 
interest  in  dairying  and  dairy  products. 

Dairy  Farm  Inspection. — Farm  inspection  is  undertaken  to  make 
sure  that  the  milk  comes  from  well-fed,  healthy  cows  kept  in  sanitary 
surroundings  and  that  the  milk  is  properly  cooled  and  cared  for  till  it 
leaves  the  farmer's  hands.  If  the  inspection  is  of  the  right  sort,  its  value 
is  very  great.  It  must  be  educative.  The  farmer  is  dairying  to  make 
money;  therefore,  he  is  interested  primarily  in  making  his  place  conven- 
ient to  work  in,  in  his  cow,  in  feeding,  in  ensiling,  in  soiling  and  in  practical 
farm  management.  The  inspector  who  can  advise  him  in  these  matters 
has  an  advantage.  The  farmer's  interest  in  sanitation  becomes  something 
more  than  perfunctory  only  when  he  can  be  shown  that  it  pays.  That 
it  does,  becomes  apparent  if  the  code  makes  it  necessary  to  attain  a 
certain  minimum  score  to  get  a  license  to  sell  milk  and  if  the  high  scores 
are  published  so  that  the  public  gives  its  trade  to  the  dairymen  who  make 
them.  The  relationship  becomes  still  more  clear  if  contractors  give 
premiums  for  high  scores  and  low  bacterial  counts  or  if  the  milk  is  graded. 
The  relationship  between  the  pocket  nerve  and  milk  quality  is  clearly 
shown  by  the  experience  of  New  York  City  with  grade  A  milk.  The 
very  men  who  could  not  be  moved  by  legislation  or  educatory  effort  to 
produce  aught  but  unclean  milk  are  putting  out  this  highest  grade  of 
milk  now  that  it  commands  a  better  price  on  the  market  than  ordinary 
milk.  This  suggests  that  a  proper  function  of  the  department  of  milk 
control  is  to  develop  a  good  market  for  milk  and  to  protect  it  from  the 
inroads  of  unfair  competition. 

In  starting  dairy  inspection  a  reasonable  time  should  be  given  farmers 
and  others  to  make  the  alterations  necessary  to  comply  with  the  ordi- 
nance. A  little  capital  at  least  and  sometimes  a  good  deal  is  required 
for  the  improvements  so  that  it  is  but  fair  to  proceed  slowly.  The  scoring 
of  dairies  should  be  done  in  the  presence  of  the  farmer  and  a  carbon  copy 
of  the  score  should  always  be  left  with  him.  It  is  well  to  establish  the 
rule  that  complaints  about  the  inspection  shall  be  based  on  the  score 
card  because  this  precludes  paltry  charges  and  leads  the  dairyman  to 
make  a  careful  study  of  his  score. 

It  has  been  said  that  inspection  is  good  but  it  cannot  be  ignored  that 
many  farmers  do  not  believe  it  to  be  so.  They  maintain  that  it  is  over- 
done, that  they  are  bothered  by  a  flock  of  inspectors  from  the  contractors, 
the  cities  and  the  State  who  are  not  agreed  among  themselves,  who 
therefore  give  contradictory  instructions  and  who  are  a  time-consuming 
pestiferous  lot.  In  some  instances  there  may  be  justice  in  this  complaint 
but  the  dairies  that  are  underinspected  far  outnumber  those  that  are 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  429 

overinspected.  It  is  certainly  important  that  inspectors  working  in 
the  same  district  should  have  like  standards  and  work  in  harmony. 
Inspectors  for  contractors  can  be  very  useful  by  preparing  the  farmer's 
mind  for  the  instruction  the  official  inspector  has  to  give.  Thus  an 
inspector  for  a  dairy  company  by  discussing  bovine  tuberculosis  thor- 
oughly with  the  dairymen  may  put  them  in  a  receptive  mood  to  advance 
the  plans  of  a  city  or  State  to  fight  the  disease. 

Inspection  of  Milk  in  Transit. — Inspection  of  milk  in  transit  is  chiefly 
concerned  with  seeing  that  the  vehicles  it  is  carried  in  are  clean  and 
sweet,  that  the  milk  is  sealed  to  prevent  it  being  tampered  with,  that  it 
is  protected  from  the  sun  and  dirt  and  that  it  is  kept  cool.  Inspection 
at  railroad  terminals  is  usually  limited  to  seeing  that  the  milk  arrives 
at  low  temperature,  to  sampling  the  milk  on  arrival,  to  seeing  that  it  is 
promptly  handled  and  that  everything  is  kept  in  good  sanitary  condition. 
Besides,  it  is  ascertained  that  the  empty  cans,  etc.,  are  returned  clean, 
unrusted  and  unbattered. 

Milk  Plant  Inspection. — The  inspection  of  milk  plants  is  very  impor- 
tant for  while  the  milk  that  leaves  the  plant  can  never  be  a  whit  better 
than  that  which  comes  in,  it  may  be  considerably  worse  if  it  is  not  handled 
promptly  and  properly  in  clean  utensils,  unless  the  plant  is  kept  scrupu- 
lously clean  and  sufficient  refrigeration  is  provided.  All  plants  should  be 
scored  on  the  card  gotten  up  for  that  purpose  by  the  Federal  Government. 
In  case  the  milk  is  pasteurized  the  apparatus  needs  special  attention. 
Care  should  be  taken  to  see  that  continuous  temperature  recorders  are 
in  use  and  that  the  milk  is  exposed  for  the  proper  time  to  the  prescribed 
temperatures.  Any  indication  that  repasteurization  of  milk  is  practised 
should  be  followed  up  and  the  custom  stopped.  Any  filthy  habits  that 
are  observed  in  the  employees  should  be  called  to  the  attention  of  the 
manager.  The  general  sanitary  environment  of  the  plant  should  be 
investigated  and  it  should  be  determined  that  the  toilet  accommodations 
are  adequate  and  sanitary.  The  expenses  of  a  milk  plant  are  heavy, 
consequently  the  manager  usually  welcomes  suggestions  that  promise 
to  effect  saving.  The  effort  should  be  made  to  keep  the  milk  plant  in 
touch  both  with  its  producers  and  the  public. 

In  inspecting  city  milk  plants  it  should  be  determined  whether  the 
plant  itself  is  suitable  for  the  conduct  of  the  business  and  whether  it  is 
adequately  equipped.  There  is  no  doubt  but  that  in  the  past  producers 
have  been  blamed  for  all  of  the  dirty  milk  that  finds  its  way  into  the  city 
market  and  the  responsibility  of  the  city  dealer  for  a  large  share  of  it 
either  has  been  unrecognized  or  ignored.  In  particular,  those  small 
city  dealers  who  are  attempting  to  operate  on  too  small  capital  are 
accountable  for  a  great  deal  of  it  and  have  been  dealt  with  too  leniently. 
The  efforts  of  a  poor  man  to  make  a  living  out  of  a  little  milk  business 
excite  sympathy,  consequently  such  men  have  been  allowed  to  conduct 


430  CITY  MILK  SUPPLY 

their  trade  from  quarters  that  were  wholly  unfit  for  the  purpose  and 
with  so  little  equipment  that  it  was  impossible  to  handle  the  milk  prop- 
erly. The  milk  they  put  out  is  often  of  poor  quality  and  their  sources 
of  supply  are  usually  unsatisfactory  and  uncertain.  Taken  by  and 
large  this  class  of  men  make  a  bare  living  out  of  the  milk  trade  only  by 
aid  of  the  unpaid  labor  of  the  members  of  the  family.  So  while  it  seems 
harsh  to  shut  them  out,  it  is  necessary  for  their  own  good  and  for  that 
of  the  community,  for  their  participation  lowers  the  tone  of  the  milk 
trade  as  a  whole.  A  minimum  standard  of  construction  and  equipment 
of  city  milk  plants  and  a  minimum  score  should  be  required  and  rigidly 
adhered  to. 

Oversight  of  the  Delivery  System. — It  is  necessary  to  keep  an  over- 
sight over  the  delivery  of  milk.  If  the  delivery  of  dipped  or  bulk  milk 
is  permitted,  the  effort  should  be  made  to  have  it  handled  in  containers 
that  protect  it  from  the  dust  of  the  streets  and  that  make  for  its  being 
handled  in  a  cleanly  manner.  This  sort  of  delivery  is  rapidly  disappear- 
ing; in  many  cities  both  large  and  small  it  is  absolutely  prohibited,  de- 
livery in  bottles  being  required.  In  spite  of  the  loss  from  breakage  and 
theft,  the  expense  of  cleaning  and  the  extra  weight  of  the  bottles  on  the 
wagon,  bottled  milk  is  superseding  dipped  milk  because  it  offers  milk  of 
uniform  composition  in  attractive  packages,  reduces  the  loss  incident 
to  handling  the  milk,  and  minimizes  the  danger  of  contamination  in 
delivery.  On  the  whole  it  is  a  much  safer  way  of  handling  milk  than  to 
deliver  it  in  bulk,  though  communities  that  do  not  require  the  daily  sterili- 
zation of  the  bottles  before  they  are  filled  are  certain  sooner  or  later  to 
suffer  from  outbreaks  of  communicable  disease  originating  in  infected 
milk  bottles.  There  should  be  a  stringent  rule  forbidding  the  filling  of 
milk  bottles  by  drivers  on  the  streets. 

Delivery  of  milk  in  open  wagons  should  be  prohibited.  The  wagons 
should  be  kept  clean  and  in  good  order.  The  noisy  delivery  of  milk  in 
the  early  morning  hours  is  a  veritable  nuisance  which  some  cities  deal 
with  by  ruling  rattlety  wagons  off  the  street  and  requiring  all  wagons  to 
be  rubber-tired.  The  drivers  should  be  neat  and  clean  and  should  be 
sharply  brought  to  book  if  detected  in  handling  milk  carelessly. 

The  provisions  of  the  code  pertaining  to  labeling  should  be  enforced. 
The  wagons  should  carry  the  name  of  the  dairy  or  of  the  owner  in  large 
plain  letters  and  the  license  number  in  bold  figures.  Some  cities  require 
that  the  name  of  the  dealer  be  moulded  in  the  bottle  and  forbid  dealers 
using  one  another's  bottles.  If  skim-milk,  subnormal  milk,  or  milk 
beverages  are  carried  on  the  delivery  wagon,  their  containers  should  be 
marked  conspicuously  as  to  their  content.  If  the  law  requires  that  the 
grade  of  milk  or  information  regarding  the  pasteurization  of  milk  be 
marked  on  the  bottle  cap,  the  caps  should  be  approved  by  the  department 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


431 


of  milk  control.     A  firm  stand  should  be  taken  against  false  or  misleading 
labeling. 

The  bureau  should  be  informed  as  to  whether  one  or  two  deliveries 
a  day  are  made,  approximately  the  territory  each  dealer  covers,  the 
number  of  wagons  he  employs,  the  length  of  time  the  milk  is  on  the  wagon, 
its  temperature  when  delivered  to  the  consumer  and  what  is  done  with 
the  milk  that  is  returned  undelivered  to  the  milk  plant.  It  should  be 
assured  that  the  regulations  in  regard  to  the  removal  of  bottles  from 
premises  harboring  cases  of  communicable  disease  are  complied  with. 


Courtesy  of  J.  O.  Jordan. 

FIG.  61. — Sale  of  dipped  milk  in  a  small  shop.     Note  that  the  top  of  the  milk  tank 

is  foul  from  milk  splashings.  ^ 

Sale  of  Milk  in  Stores. — The  sale  of  milk  in  stores  ought  to  be  closely 
watched.  Generally  it  is  small  provision  stores  in  the  poorer  and  more 
congested  parts  of  the  city  that  deal  in  milk  and  usually  they  carry  it 
rather  for  the  accommodation  of  their  patrons  than  with  the  expectation 
of  making  money  out  of  it;  therefore,  they  take  little  care  of  it.  The 
stores  themselves  are  often  poorly  furnished  and  cluttered  with  all  sorts 
of  small  merchandise,  consequently  they  are  unclean  and  smelly.  In 
short,  the  sale  of  milk  in  them  is  to  be  tolerated  rather  than  encouraged. 
Yet  they  do  considerable  trade.  The  replies  to  letters  of  inquiry  sent 
out  by  the  U.  S.  Department  of  Agriculture  in  1911,  to  47  cities  having 
an  aggregate  population  of  451,239,  showed  that  these  cities  averaged 
1,256  milk-selling  stores  or  one  store  to  every  359  inhabitants.  Of  these 


432  CITY  MILK  SUPPLY 

stores,  52.4  per  cent,  sold  only  bottled  milk,  while  the  rest,  or  47.6  per 
cent.,  sold  dipped  milk.  In  17  cities  reporting,  the  dipped  milk  sold  over 
the  counter  per  day  amounted  to  231,896  gal.,  or  13,641  gal.  per  day  in 
each  city  permitting  the  practice. 

There  are  numerous  objections  to  the  sale  of  dipped  milk.  It  is  apt 
to  be  stale  because  drivers  commonly  deliver  that  milk  which  has  been 
longest  on  the  wagon  to  the  stores  and  the  fresh  milk  to  the  family  trade. 
Even  if  the  intention  of  the  dealer  is  honest  the  quality  of  the  milk  served 
to  different  customers  will  vary  considerably;  some  will  get  rich  milk 
from  the  top  of  the  can  and  others  will  get  skim-milk  from  the  bottom. 
A  more  weighty  objection  to  the  sale  of  dipped  milk  is  found  in  the  records 
of  several  cities  which  show  that  the  samples  of  dipped  mjlk  from  stores 
are  much  more  .commonly  adulterated  in  other  ways  than  by  skimming 
than  are  the  samples  from  wagons.  Besides  being  liable  to  sophistica- 
tion dipped  milk  is  exposed  to  contamination  with  all  sorts  of  dirt.  Often 
facilities  for  cleaning  the  milk  utensils  are  lacking  and  so  the  dipper  and 
measure  get  into  shocking  condition;  sometimes  a  cheesy  layer  of  casein 
accumulates  at  the  edges  of  the  milk  tank  and  sediment  collects  on  the 
bottom.  Most  serious  of  all  is  it,  that  the  milk  is  repeatedly  exposed  to 
human  contamination  and  therefore  is  likely  to  become  infected  with 
the  germs  of  human  disease.  The  proprietors  of  the  stores  are  often 
ignorant  and  have  no  conception  of  the  way  milk  should  be  handled  and 
so  it  is  insufficiently  iced  or  iced  not  at  all.  The  result  is  the  bacterial 
content  of  dipped  milk  is  likely  to  be  very  high.  Thus  in  Boston  in 
1908,  only  27.85  per  cent,  of  the  wagon  samples  contained  more  than 
500,000  bacteria  per  cubic  centimeter,  whereas  56.59  per  cent,  of  samples 
of  dipped  milk  ran  over  this  figure. 

Some  cities  absolutely  prohibit  the  sale  of  dipped  milk  but  not  all  are 
able  to  do  so.  Its  sale  has  to  be  tolerated  because  the  very  poor  cannot 
purchase  bottled  milk  and  find  the  dipped  milk  a  convenience.  These 
people  buy  a  few  cents  worth  of  milk  at  a  time,  take  it  home  and  use  it 
at  once.  Even  if  they  could  afford  to  buy  milk  by  the  bottle,  they  have 
no  way  to  keep  it  cool  so  that  most  of  it  would  spoil  before  being  used. 
In  some  places  this  difficulty  is  met  by  selling  milk  to  stores  in  K-pt- 
bottles.  Undoubtedly  one  of  the  reasons  that  both  milk  dealers  and 
storekeepers  are  loth  to  discard  the  sale  of  dipped  milk  is  that  serious  loss 
is  suffered  from  the  non-return  of  bottles.  Where  this  can  be  controlled 
by  requiring  a  deposit  for  the  bottle  much  of  the  opposition  to  the  dis- 
continuance of  the  sale  of  dipped  milk  disappears.  Generally  the  effort 
of  the  department  should  be  to  gradually  eliminate  the  sale  of  dipped  milk 
and  meanwhile  to  control  the  sale  by  scoring  the  stores  on  the  score  card 
devised  by  the  U.S.  Department  of  Agriculture  and  by  frequent  inspections. 

When  dealers  substitute  the  sale  of  milk  in  bottles  for  that  of  dipped 
milk  they  soon  are  pleased  with  the  change,  for  the  bottles  are  easy  to 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


433 


SANITARY  INSPECTION  OP  STORES  HANDLING  BULK  MILK,  U.  S.  DEPARTMENT  OF 

AGRICULTURE,  BUREAU  OF  ANIMAL  INDUSTRY,  DAIRY  DIVISION 

DETAILED  SCORE 


Sc( 

)re 

Sec 

re 

Equipment 

Perfect 

Allowed 

Methods 

Perfect 

Allowed 

Building 

Building 

10 

laminating  surroundings  .  . 

2 

Floor  3 

Separate    room    for    milk 

Wall  2 

5 

8 

Ceiling                                  2 

Floors     tight,     smooth, 
cleanable  1 
Walls      tight,      smooth, 
cleanable                           1 

Showcases,  shelves,  etc.   3 

3 

Ceilings    tight,    smooth, 
cleanable                           1 

2 

Show  cases  smooth,  free 

Air  

4 

from  ledges  and  crevices  1 

Freedom  from  dust  2 

Provision  for  light  (10 
per  cent,  of  floor  space)  1 
Provision  for  pure  air        1 

Freedom  from  odors  2 
Utensils 

20 

Screens       .                          2 

Utensils  
Construction:  Easily 
cleaned;  free  from  open 
seams   and   complicated 
parts  5 
Condition:  Free  from  rust, 
dents,  etc  2 

Facilities  for  cleaning: 
Water  clean,  convenient, 

15 

rinsed  10 
Steamed  10 
(Scalded,  5.) 

Ice  box  
Cleanliness  of  ice  box  

Handling: 

Placed  on  ice  as  soon  as  re- 
ceived   

3 
5 



and  abundant  2 
Hot  water  or  steam  ....    3 

•  Brushes     and     washing 
powder  1 

(Protected,   put    on   ice 
inside  of  an  hour,  2.) 

(Unprotected,  but  put  on 
ice  inside  of  an  hour,  1.) 

Protected   from    flies    and 
dust  when  not  in  use.  .  .    2 

Temperature  of  milk,  be- 
low 50°F 

10 

Ice  box  

10 

(51-55,  8;  56-60,  5;  61- 
65,  2  ) 

(Milk  kept  in  separate 

Freedom  from  undue  ex- 
posure to  air 

2 

Cleanliness  of  attendants  

1 

Construction  3 

Tight  and  cleanable  1 
Non-absorbent  lining.  .  .    1 
Good  drainage  1 
Protected   from    flies    and 
dust  2 

Total 

40 

Total 

60 

Equipment +  Methods =  Total 

NOTE. — If  the  conditions  in  any  particular  are  so  exceptionally  bad  as  to  be  inadequately  expressed 
by  a  score  of  "0,"  the  inspector  can  make  a  deduction  from  the  total  score. 


434  CITY  MILK  SUPPLY 

handle  and  friction  with  the  authorities  over  skim-milk,  etc.,  is  reduced  to 
a  minimum. 

In  Massachusetts  the  State  Supreme  Court  found  that  the  Board 
of  Health  of  the  City  of  Boston  had  exceeded  its  powers  in  prohibiting 
the  sale  of  dipped  milk,  but  before  the  decision  was  announced  the  ordi- 
nance had  been  in  force  long  enough  to  demonstrate  its  wisdom  and  no 
one  has  cared  to  resume  the  sale  of  milk  in  bulk. 

Stores  selling  bottled  milk  must  needs  be  inspected,  too.  It  is  im- 
portant to  see  that  bottles  are  not  filled  on  the  premises  and  that  the  prac- 
tice of  splitting  bottles  of  milk  is  not  indulged  in.  It  must  be  ascertained 
that  the  milk  is  stored  properly  for  there  is  danger  that  the  bottles  may 
stand  around  the  store  uniced.  Stores  selling  bulk  milk  should  be 
scored  on  the  Federal  Dairy  Division  score  card,  designed  for  that  purpose. 

Milk  in  the  Home. — By  attention  to  these  various  phases  of  the 
dairy  business,  health  departments  reach  the  dairy  farmers,  the  milk 
contractors  and  the  vendors  of  milk  and  help  them  to  serve  the  public 
with  milk  of  good  quality.  It  remains  to  interest  the  milk  consumers 
and  to  get  them  to  do  their  part  in  maintaining  a  good  milk  supply. 
Some  boards  do  this  by  issuing  leaflets  on  the  value  of  milk  as  a  food,  on 
the  care  of  milk  in  the  home  and  like  topics.  The  effort  is  made  to  get 
the  housekeeper  to  realize  that  the  best  of  milk  will  spoil  quickly  unless  it 
is  kept  properly  and  so  that  if  she  is  neglectful  her  family  must  be  content 
with  poor  milk.  In  some  places  the  misuse  of  milk  bottles  has  been 
greatly  lessened  by  urging  people  to  be  careful  to  return  them  whole  and 
clean  and  by  pointing  out  that  excessive  waste  of  bottles  tends  to  raise 
the  price  of  milk.  Sometimes  boards  have  helped  the  public  by  showing 
it  to  be  impossible  to  sell  good  milk  at  prevailing  market  prices  and 
helping  to  establish  rates  high  enough  for  the  dairymen  to  be  clean  and 
honest.  Wherever  boards  win  public  confidence  they  are  frequently 
consulted  as  to  the  quality  of  milk  put  out  by  different  dealers.  To 
answer  such  questions  the  board  must  have  a  laboratory  and  make  many 
milk  analyses. 

Laboratory  Tests. — The  States,  most  of  the  large  cities  and  many  of 
the  small  ones  support  laboratories  for  bacteriological  diagnosis  and 
the  testing  of  foods  including  milk.  Indeed,  this  sort  of  work  has  become 
so  important  that  to  secure  its  benefits  contiguous  towns  not  large 
enough  to  support  laboratories  of  their  own  combine  and  support  a  single 
laboratory  that  serves  them  all.  The  milk  tests  that  are  commonly 
made  in  these  laboratories  are  of  three  principal  kinds,  namely:  physical, 
chemical  and  biological.  The  object  in  applying  these  tests  is  to  keep 
dirty,  decomposed  and  adulterated  milk  off  the  market. 
>  Sediment  Test. — The  two  principal  physical  tests  of  milk  are  the 
sediment  and  the  lactometer  tests.  In  fact,  many  small  towns  that 
cannot  afford  laboratory  facilities  rely  solely  on  these  two  tests  to  keep 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  435 

dirty,  watered  and  skimmed  milk  off  the  market.  That  they  in  some 
measure  do  this  is  not  to  be  doubted  but  the  sediment  of  dirty  milk  can 
be  greatly  reduced  by  careful  straining  and  by  centrifugalizing  the 
milk,  and  milk  can  be  doctored  by  the  use  of  condensed  milk  and  by 
other  means  to  meet  the  lactometer  test  so  that  only  in  a  limited  way  do 
these  tests  detect  dirt  and  fraud.  The  sediment  test  is  usually  performed 
by  passing  a  pint  of  milk  through  a  Wisconsin  or  a  Wizard  sediment 
tester.  The  sediment  is  caught  on  cotton  disc  which  may  be  dried  and 
preserved.  The  test  is  one  that  every  dairyman  can  grasp  the  meaning 
of  and  it  has  been  used  very  effectively  not  only  by  city  officials  but  by 
creameries  and  cheese  factories  to  get  cleaner  milk.  It  is  the  practice 
of  some  offices  to  mail  excessively  dirty  discs  to  the  offending  producer 
with  an  injunction  that  he  mend  his  ways.  Some  health  officers  preserve 
the  discs  and  mount  them  on  a  card  to  be  filed  as  part  of  the  permanent 
record  of  the  dairyman ;  others  at  intervals  prepare  a  mount  of  the  discs 
of  all  the  dairymen  in  town  and  display  it  in  the  health  office  or  in  some 
store  window  where  all  who  pass  can  see  it. 

Lactometer  Test. — The  lactometer  is  a  float  for  taking  the  specific 
gravity  of  milk.  *  There  are  two  lactometers  in  use  in  this  country, 
the  New  York  Board  of  Health  and  the  Quevenne;  they  differ  principally 
in  the  scales  on  the  stem  for  reading  the  specific  gravity.  The  Quevenne 
i$  probably  in  most  general  use;  on  its  scale  most  normal  milks  give  read- 
ings between  30  and  34. 

Chemical  Tests. — The  chemical  determinations  that  are  ordinarily 
made  in  examining  milk  are  the  butterfat,  the  total  solids  and  the  ash. 
The  solids-not-fat  are  obtained  by  difference.  The  acidity  of  milk  is 
easily  determined  by  titrating  it  with  an  alkali  and  with  phenolphthalein 
as  an  indicator.  The  acidity  is  usually  expressed  as  percentage  of  lactic 
acid.  In  the  larger  laboratories,  if  skimming  is  suspected,  proteins  are 
determined  by  the  Gunning  method,  if  watering  the  refraction  of  the 
serum,  the  lactose,  the  soluble  albumen,  and  the  sour  serum  ash. 

Tests  for  Preservatives. — Tests  for  preservatives  in  milk  are  made  at 
most  laboratories.  Formerly  this  kind  of  adulteration  was  very  common 
but  partly  because  of  the  vigor  of  the  campaign  against  it  and  partly 
because  dairymen  have  learned  to  produce  milk  that  will  keep,  the  doping 
of  milk  has  gone  out  of  fashion.  The  preservatives  most  commonly 
used  are  formaldehyde,  borax,  borates,  boracic  acid,  salicylic  acid,  ben- 
zoic  acid,  benzoates,  sodium  bicarbonate,  fluorids,  hydrogen  peroxid 
(Buddeized  milk),  nitrates,  potassium  bichromate,  etc.  To  cream,  cal- 
cium sucrate  (viscogen)  is  sometimes  added  to  thicken  it;  so  is  gelatin 
and  possibly  starch.  Anatto  and  the  coal-tar  dyes,  principally  the 
azo-colors,  are  sometimes  used  to  make  milk  look  rich. 

Biological  Tests. — Determination  of  the  Cellular  Content. — Biological 
examination  of  milk  is  divided  into  two  parts,  namely :  the  determination 


436  CITY  MILK  SUPPLY 

of  the  cellular  content,  and  the  bacteria.  For  the  former  the  methods 
of  Prescott  and  Breed,  of  Doane  and  Buckley  as  improved  by  Hastings, 
or  of  Stewart  are  used.  Of  the  three  the  Stewart  method  is  the  least 
exact.  However,  it  is  the  most  convenient  and  the  information  obtained 
from  the  microscopical  examination — of  the  smeared  sediment,  although 
it  is  not  accurate  enough  for  quantitative  work,  is  satisfactory  for 
qualitative  examinations  and  so  has  proved  very  helpful  in  routine  labora- 
tory practice.  Slack  first  advocated  a  microscopical  estimate  of  bac- 
teria by  an  adaptation  of  the  Stewart  method  for  cells.  The  method  of 
Prescott  and  Breed  shows  the  greatest  number  of  cells  and  has  the  ad- 
vantage that  the  smear  can  be  used  also  for  microscopical  counting  of 
bacteria. 

Stokes  and  Wegefarth  in  1897  called  attention  to  the  leukocytes  in 
market  milk  and  took  the  ground  that  milk  containing  more  than  five 
leukocytes  to  a  field  of  a  2-mm.  objective  was  unfit  for  use.  They  spoke 
of  the  leukocytes  as  pus  cells  and  the  inference  was  widely  drawn  that 
the  presence  of  large  numbers  of  these  cells  indicated  that  the  milk  came 
from  cows  with  inflamed  udders.  Subsequent  investigations  showed 
this  view  to  be  fallacious;  cows  giving  no  history  of  udder  trouble  and 
in  perfectly  normal  health  were  found  to  give  off  body  cells  which  are 
mostly  leukocytes  but  partly  epithelial  cells,  at  times  in  great  numbers. 
The  leukocytes  themselves  occur  normally  in  the  blood  and  lymphatics 
and  make  their  way  from  these  into  most  of  the  other  body  tissues  so 
that  they  can  be  correctly  spoken  of  as  pus  cells  only  when  they  can  be 
shown  to  be  derived  from  suppurative  discharges. 

It  is  generally  accepted  that  if  the  Stewart-Slack  smear  shows  the 
intimate  association  of  long-chain  streptococci  with  bunched  leukocytes, 
it  may  be  safely  concluded  that  the  organisms  are  pyogenic  streptococci 
derived  from  cases  of  garget  and  that  the  milk  should  be  withheld  from 
the  market  until  the  affected  animals  are  located  and  removed  from  the 
herd.  The  health  department  of  the  city  of  Boston,  Mass.,  began  ex- 
cluding milk  from  the  city  on  this  test  in  1905.  That  year  10.5  per  cent, 
of  the  5,500  samples  of  market  milk  examined  were  found  infected  with 
the  streptococci.  At  that  time  milk  was  excluded  that  showed  "pus" 
without  streptococci  or  streptococci  without  "pus,"  later  a  more  conserva- 
tive attitude  was  taken  and  only  milk  showing  pus,  or  bunched  leukocytes 
associated  with  streptococci  was  excluded.  In  1906  the  number  of 
positives  dropped  to  4.9  per  cent,  and  in  1907  to  1.1  per  cent,  and  has 
remained  less  than  2  per  cent,  ever  since,  usually  being  about  1  per 
cent.  Many  times  the  justice  of  the  Board's  action  has  been  confirmed 
by  tracing  the  milk  back  to  the  farm  that  supplied  it  and  finding  cows 
with  diseased  udders  in  the  herd. 

In  making  bacterial  counts  by  his  method,  of  milk  brought  in  by 
farmers,  Breed  very  recently  has  found  enormous  numbers  of  long 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  437 

chain  streptococci  in  some  of  the  milk,  and  in  every  instance  where  he 
traced  it  back  to  the  farm,  found  one  or  more  infected  udders  in  the  herd, 
but  of  9,387  cows  that  he  examined  309  or  3.3  per  cent,  were  positive; 
4  out  of  40  herds  supplying  the  milk  were  badly  affected  and  but  8  out 
of  the  30  dairymen  who  furnished  milk  continuously  for  twenty  months 
did  so  without  bringing  any  streptococcic  milk. 

Garget  due  to  streptococcal  and  to  other  bacterial  invasions  of  the 
udder  is  very  common,  but  from  our  present  knowledge  of  septic  sore 
throat  there  is  no  reason  to  believe  that  the  disease  is  derived  from  the 
ordinary  run  of  garget  cases.  Practically  always,  it  seems  to  be  due  to 
the  Smith  streptococcus  which  may  infect  the  cow's  udder  from  human 
sources.  Outbreaks  of  diarrhea  have  been  produced  by  streptococci 
coming  from  the  udders  of  cows  suffering  with  mammitis.  So  there  is 
good  reason  for  removing  cows  with  udder  trouble  from  the  herd.  When 
such  animals  shall  be  returned  to  the  herd  is  usually  left  to  the  judg- 
ment of  the  herdsman,  who  makes  his  decision  on  the  appearance  of  the 
udder  and  of  the  milk.  The  wisdom  of  this  procedure  is  doubtful  for 
the  infective  organisms  often  persist  long  after  physical  evidence  of  their 
presence  has  disappeared. 

Biological  Test  for  Heated  Milk. — Frost  has  proposed  the  folio  wing 
method  for  detecting  pasteurized  milk  by  direct  microscopical  examina- 
tion. One  part  of  a  saturated  aqueous  solution  of  methylene  blue  is 
slowly  added  from  a  pipette  to  5  parts  of  milk,  the  milk  being  rotated  in 
a  flask  during  the  addition  to  prevent  coagulation  of  the  milk  which 
vitiates  the  test.  After  15  to  30  min.  the  stained  milk  is  centrifuged  in 
Slack  tubes  or  ordinary  urine  tubes  and  the  sediment  is  smeared  on  glass 
slides  and  dried  when  the  smear  is  ready  for  examination. 

The  stain  is  made  up  by  adding  7  grains  of  Gruebler's  dry  dye  to 
100  c.c.  of  distilled  water  and  allowing  it  to  stand  several  hours  with 
frequent  shakings.  Finally,  it  is  filtered. 

The  differentiation  between  pasteurized  and  unpasteurized  milk 
depends  upon  a  twofold  change  effected  by  heat  on  the  leukocytes,  viz. : 
(1)  it  alters  the  shape  and  size  of  the  cells;  and  (2)  it  changes  their  staining 
reactions. 

The  smear  from  the  unpasteurized  milk  under  the  low  power  of  the 
microscope  gives  a  light  blue  field  in  which  the  depth  of  the  stain  depends 
on  the  thickness  of  the  film  but  which  very  uniformly  is  stained  more 
highly  than  any  of  the  smaller  objects  in  the  field.  The  oil  immersion 
lens  shows  the  mononuclear  cells  well-stained  and  they  are  not  considered 
in  this  test. 

The  polymorphonuclear  cells  are  distinguished  with  some  difficulty 
and  appear  colorless,  of  irregular  outline  and  12/x  in  diameter.  If  the 
nuclear  material  is  differentiated  at  all,  it  is  not  well-defined. 

The  smear  from  pasteurized  milk  under  low  power  appears  less 


438  CITY  MILK  SUPPLY 

deeply  stained,  excepting  the  thick  portions,  than  the  unheated  milk  and 
the  leukocytes  take  the  stain  more  deeply  than  the  background  so  that 
they  appear  as  dark  blue  areas  in  a  light  blue  field.  Often  there  is  a 
halo  about  the  leukocytes  owing  to  the  background  immediately  sur- 
rounding them  staining  deeply  and  shading  off  into  the  general  color  of 
the  smear.  The  oil  immersion  lens  shows  the  polymorphonuclear  cells 
readily,  with  less  irregular  outline  than  those  of  the  raw  milk  and  shrunken 
to  about  ?M  in  diameter.  The  nuclei  are  distinctly  stained.  The  amount 
of  the  shrinking  and  the  depth  of  the  stain  vary  some  with  the  degree  of 
heat  applied.  The  shrinking  of  the  cells  begins  at  a  lower  temperature 
than  that  used  for  pasteurization  and  their  shape  gradually  changes  as 
the  degrees  of  heat  increase.  The  fixing  of  the  nuclear  material  which 
makes  possible  the  absorption  of  the  stain  seems  to  take  place  at  between 
140°  and  145°F.,  the  temperature  used  in  the  holder  process  of  pasteuriza- 
tion. The  changes  Frost  points  out  as  characteristic  of  heated  milk  are 
observable  in  the  Stewart-Slack  smears,  so  those  that  use  them  say,  and 
they  hold  that  the  smears  may  be  used  for  detecting  heated  milk. 

The  Bacteria  Count. — It  is  but  recently  that  the  bacterial  content  'of 
milk  has  been  used  as  a  criterion  of  milk  quality.  The  first  bacterial 
count  of  a  municipal  milk  supply  to  be  published  in  the  United  States 
were  those  of  Sedgwick  and  Batchelder  who  in  1892  gave  out  the  results 
of  their  study  of  the  milk  of  Boston.  At  about  the  same  time  Conn 
published  the  counts  he  obtained  in  investigating  the  milk  supply  of 
Middletown,  Conn.  Other  bacteriologists  took  up  the  work  and  before 
long  many  cities  were  making  regular  bacteriological  examinations  of  the 
milk  served  the  public.  Montclair,  N.  J.,  was  the  first  municipality  to 
regularly  publish  the  results  of  such  examinations.  There  the  effect  was 
that  the  public  became  interested  at  once  and  began  to  favor  those  dealers 
whose  milk  had  low  counts.  Soon  cities  began  to  establish  bacteriological 
milk  standards.  Thus  New  York  City  in  1900  adopted  a  maximum 
limit  of  1,000,000  bacteria  per  cubic  centimeter  and  Boston  a  little  later 
established  a  limit  of  500,000  bacteria  per  cubic  centimeter.  Other 
cities  followed  so  that  in  1914  the  U.  S.  Public  Health  Service  was  able 
to  publish  a  list  of  149  cities,  each  having  a  population  of  over  10,000  and 
having  together  a  population  of  somewhat  over  21  million,  that  had  set 
up  bacteriological  standards  of  some  sort. 

There  is  no  question  but  that  the  bacterial  count  has  been  very 
effective  in  improving  many  milk  supplies.  The  result  of  publishing 
counts  has  been  to  focus  public  attention  on  clean  methods  of  milk 
production  and  on  the  proper  care  of  the  milk  and  this  has  reacted  on 
producers  and  dealers,  making  them  emulate  the  methods  of  the  best 
dairymen.  Notwithstanding  this,  some  bacteriologists  question  the 
wisdom  of  laying  great  stress  on  the  bacterial  count  on  the  ground  that  it 
is  inexact  and  illogical. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


439 


Methods  of  Making  the  Bacterial  Count. — There  are  three  methods  of 
making  bacterial  counts,  namely:  (1)  by  the  plate  method  of  Koch; 
(2)  by  the  direct  method  of  counting  the  bacteria  in  a  smear  prepared 
according  to  the  Breed  method,  or  by  the  less  accurate  method  of  Slack; 
and  (3)  according  to  the  stained  incubated  slide  method  of  Frost.  The 
Koch  method  is  the  standard  one;  it  consists  of  growing  the  organisms 
at  a  chosen  temperature  and  for  a  definite  time  usually  at  68°F.  for 
48  hr.  in  specially  prepared  nutrient  media  in  petri  dishes  and  counting 
the  organisms  that  develop.  The  summary  of  the  advantages  and  dis- 
advantages of  the  Breed  and  of  the  Koch  plate  methods  as  given  by 
Brew  appears  in  Table  117. 

TABLE  117. — THE  DISADVANTAGES  AND  ADVANTAGES  OP  THE  MICROSCOPICAL  AND 
METHODS  OP  PLATE  MAKING  BACTERIAL  COUNTS  COMPARED  (BREW) 

Disadvantages 
Breed  method 

1.  Difficult  to  measure  so  small  a  quan- 
tity of  milk  accurately. 

2.  The  sample  measured  is  too  small  to 
be  representative. 

3.  Dead  bacteria  may  be  counted. 

4.  Error  of  count  is  great  where  bac- 
teria are  very  few  or  many. 

5.  Cannot    be   used   for    quantitative 
work    when    the    bacteria    are    few    in 
number. 

6.  Many  fields  must  be  counted,  be- 
cause of  the  uneven  distribution,  if  an 
accurate  count  is  required. 

7.  Large  compact  clumps   cannot  be 
counted. 

8.  Bacteria  may  be  lost  in  process  of 
preparing  slides. 


Plate  method 

1.  All  bacteria  do  not  grow  on  the 
plates  because  of  changes  in  food,  tem- 
perature relations  or  other  conditions  of 
environment. 

2.  The  difficulty  of  breaking  up  the 
clumps  in  the  milk  affects  the  accuracy 
of  the  count. 

3.  Requires  from  2  to  5  days'  incuba- 
tion period. 

4.  Different   species   require   different 
incubation  temperatures. 

5.  Gives  no  idea  of  the  morphology  of 
the  organisms  present. 

6.  More  apparatus  is  required;  there- 
fore,    is     more     expensive.     Technique 
complicated    and    difficult    for    trained 
bacteriologists  to  use  in  such  a  way  as  to 
get  consistent  results. 


Advantages 


1.  Less  apparatus  required,  therefore 
less  expensive.     Technique  simple. 

2.  The  results  on  a  given  sample  can  be 
reported  within  a  few  minutes. 

3.  Shows  the  cell  content,  the  presence 
or  absence  of  streptococci  and  other  im- 
portant things  necessary  in  estimating 
the  sanitary  quality  of  milk. 

4.  Gives  a  better  idea  of  the  actual 
number  of  germs  present. 


1.  Is  necessary  for  isolation  of  pure 
cultures. 

2.  Gelatin  shows  the  liquefiers  and  if 
litmus  is  used,  the  acid  producing  bac- 
teria. 

3.  Shows  character  of  growth. 

4.  Shows  living  organisms  only. 


There  are  two  ways  of  counting  the  Breed  smears.  By  one  method  each 
cell  in  a  chain  of  streptococci  or  in  a  clump  of  bacteria  is  counted,  with 
the  result  that  roughly  about  10  times  the  number  of  bacteria  shown  by 


440  CITY  MILK  SUPPLY 

the  plate  method,  are  found.  By  the  other,  each  clump  and  each  chain 
of  streptococci  is  counted  as  a  unit.  The  latter  method  usually  gives 
much  lower  counts  and  corresponds  more  closely  with  the  plate  count; 
it  is  the  method  adopted  by  the  Bureau  of  Chemistry  in  milk  work  when 
the  microscopical  method  is  used.  The  Slack  method  shows  approxi- 
mately as  many  bacteria  as  the  plate  method  does. 

The  standard  methods  adopted  by  the  American  Public  Health 
Association  in  1916  make  the  plate  method  the  standard  one  but  the 
usefulness  of  the  Breed  method  in  certain  lines  of  milk  work  is  recognized 
and  its  use  advised  when  direct  counting  is  undertaken. 

In  the  stained  incubated-slide  method  recently  proposed  by  Frost,  J^o 
c.c.  of  milk  is  mixed  with  standard  nutrient  agar  and  spread  over 
a  definite  area  of  a  sterile  glass  slide.  When  the  agar  is  hard,  this  little 
plate  culture  is  put  in  the  incubator  for  about  6  hr.  under  conditions  that 
prevent  evaporation.  It  is  then  dried,  given  a  preliminary  treatment  to 
prevent  the  agar  from  firmly  binding  the  stain,  stained,  decolorized  and 
cleared.  When  the  dried  and  stained  plate  culture  is  viewed  under  the 
microscope  the  little  colonies  are  definitely  stained  and  appear  highly 
colored  on  a  colorless  or  slightly  colored  background.  The  colonies 
can  be  readily  counted  and  the  number  of  bacteria  per  cubic  centimeter 
calculated. 

Accuracy  of  Bacteria  Counts. — It  has  long  been  known  that  dissimilar 
bacteriological  results  are  frequently  obtained  when  samples  of  the  same 
milk  are  submitted  to  different  laboratories  for  examination.  It  was 
felt  that  these  discrepancies  were  in  large  part  due  to  slight  differences 
in  the  media  used  and  also  to  variations  in  technique  that  obtained  in 
different  laboratories;  so  that  American  Public  Health  Association  pub- 
lished Standard  Methods  of  Milk  Analysis  which  have  been  generally 
accepted  throughout  the  United  States.  In  spite  of  these  methods  being 
used,  divergent  results  continued  to  be  obtained  and  this,  in  1914,  led 
four  laboratories  in  New  York  City,  viz.,  the  New  York  City  Public 
Health,  the  Borden,  the  North  and  the  Lederle  laboratories  to  ask  H.  W. 
Conn  of  Wesleyan  University  of  Middletown,  Conn.,  to  act  as  referee 
of  a  cooperative  test  that  lasted  7  months  and  involved  the  making  of 
about  20,000  bacterial  analyses  by  various  methods  with  the  object  of 
determining  whether  the  discrepancies  are  due  to  inevitable  difficulties 
in  bacteriological  analysis,  or  whether  such  analysis  has  such  inherent 
obstacles  that  it  cannot  be  made  reliable,  or  whether  the  different  methods 
of  technique  employed  in  the  several  laboratories  were  responsible  for 
wide  variations  in  the  result.  In  case  differences  in  technique  proved  to 
be  a  factor  of  considerable  moment,  it  was  the  intention  to  determine 
how  nearly  identical  the  various  methods  might  be  made  and  what  error 
in  bacteriological  milk  analysis  would  still  remain.  The  general  sum- 
mary and  conclusions  arrived  at  from  the  test  are  these: 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  441 

"1.  The  standard  methods  of  Milk  Analysis,  published  by  the  American 
Public  Health  Association,  are  in  emphatic  need  of  revision.  These  standard 
methods  lay  great  emphasis  on  some  of  the  least  important  points,  while  they 
neglect  to  lay  any  emphasis  on  some  of  the  most  important  ones.  The  revision 
of  these  methods  is  now  in  the  hands  of  at  least  three  committees,  one  appointed 
by  the  American  Public  Health  Association,  one  by  the  Society  of  American  Bac- 
teriologists, and  one  by  the  Association  of  Dairy  Instructors.  (Revision  of  1916 
has  since  been  adopted.) 

"2.  Individual  analyses  under  the  best  conditions  are  subject  to  considerable 
variation,  so  that  no  single  individual  count  can  be  properly  relied  upon.  This 
emphasizes  the  necessity  of  demanding  an  average  of  two  or  more  plates  in  deter- 
mining the  bacterial  content  of  any  sample  of  milk. 

"3.  The  question  of  the  exact  composition  of  the  media  to  be  used  is  of  far 
less  significance  than  that  of  the  methods  used  in  the  manipulation.  Wide  varia- 
tions in  the  composition  of  the  media  do  not  make  any  noticeable  difference  in 
the  bacterial  count.1 

"4.  Greater  care  is  needed  to  unify  laboratory  methods  than  has  hitherto 
been  given.  When  the  work  of  these  four  laboratories  was  compared  at  the  out- 
set it  was  found  that  there  were  very  wide  differences  in  the  analyses  of  duplicate 
samples,  due  chiefly  to  differences  in  laboratory  technique. 

"5.  These  variations  in  the  analyses  of  duplicate  samples  of  the  same  lot  of 
milk  have  been  found  to  be  due  to  several  causes: 

"(a)  Laboratory  errors.  These  occasionally  appear,  due  doubtless  to  con- 
fusion which  is  sure  to  arise  when  large  numbers  of  samples  of  milk  are  analyzed 
at  the  same  time. 

"  (6)  Irregularities  in  methods  of  laboratory  technique.  These  are  several  in 
number,  the  more  important  seeming  to  be  the  following: 

"I.  Shaking  of  the  samples.  Wide  variations  were  found  in  the  vigor  and 
the  extent  of  the  shaking  to  which  the  samples  of  milk  and  the  dilutions  are 
subjected  by  the  different  laboratories.  While  this  factor  does  not  make  a  very 
great  difference  in  results,  it  is  one  of  the  irregularities  that  should  be  eliminated. 

"II.  Amount  of  dilution.  The  counts  from  highly  seeded  plates  are  uni- 
formly lower  than  the  counts  of  the  same  milk  from  low-seeded  plates.  The 
best  results  are  obtained  only  when  the  plates  contain  somewhere  between  40 
and  200  colonies.  Hence  the  number  of  dilutions  made  in  any  analysis  will 
materially  affect  the  results. 

"III.  Methods  of  counting.  This  has  seemed  to  be  the  cause  of  the  widest 
amount  of  irregularity.  The  greatest  difference  was  associated  with  the  use  or 
non-use  of  a  counting  lens,  or  to  differences  in  magnifying  power  of  the  lens  used.2 

"Even  when  this  difference  is  eliminated  the  further  results  show  that  the 
personal  equation  in  counting  is  still  a  factor  of  very  large  importance.  When 

1  For  this  reason  and  in  order  to  produce  uniformity,  there  has  already  been 
adopted  by  the  American  Public  Health  Association  a  change  in  the  standard  methods 
by  which  beef  extract  can  be  substituted  for  beef  infusion  and  the  acidity  of  the  stand- 
ard agar  fixed  at  1  per  cent.,  thus  making  it  uniform  with  that  of  the  standard  used 
in  water  analyses. 

2  The  recognition  of  this  fact  has  already  led  to  a  modifying  of  the  standard  meth- 
ods, which  now  require  a  lens  of  3)^  diameters  to  be  used  in  counting  all  plates. 


442  CITY  MILK  SUPPLY 

the  same  plate  is  counted  by  two  different  laboratories  the  results  are  not  infre- 
quently 100  per  cent,  apart,  and  occasionally  even  more. 

"  A  third  factor  modifying  the  counting  is  the  method  adopted  by  each  labora- 
tory of  estimating  numbers  rather  than  actual  counting.  In  plates  that  contain 
large  numbers  of  colonies  it  is,  of  course,  necessary  to  make  an  estimate  rather  than 
to  count  them  all.  The  laboratories  adopt  different  methods  in  such  conditions, 
the  results  being  slightly  different. 

"IV.  Irregularities  in  samples  from  the  same  bottle  of  milk.  Two  samples 
taken  from  the  same  bottle  of  milk,  even  after  thorough  shaking,  are  by  no  means 
identical.  This  is  easily  explained,  and  is  due  (1)  to  the  clumping  of  bacteria 
and  (2)  to  the  fact  that  inasmuch  as  bacteria  are  not  in  solution  but  are  solid 
objects  they  cannot  be  expected  to  be  uniformly  distributed  through  the  liquid. 
The  tests  show  that  one  sample  of  a  bottle  of  milk  when  tested  by  the  plate 
method  may  sometimes  not  contain  more  than  one-fourth  as  many  bacteria  as 
other  samples  from  the  same  bottle. 

"V.  In  low  counts  variation  between  duplicate  samples  is  sometimes  con- 
siderable, due  to  the  irregularity  of  the  distribution  of  bacteria. 

"In  high  counts  variation  in  reports  is  also  sometimes  very  great,  due  to  ex- 
cessive crowding  and  to  methods  adopted  in  estimating  the  number  of  colonies. 

"6.  The  extent  of  the  variation  in  the  results  obtained  from  the  analysis  of 
duplicate  samples  varies  widely  with  the  care  that  is  taken  in  the  laboratory 
technique.  It  has  been  found  in  these  tests  that  at  first  the  above  causes  of 
irregularity  were  sufficient  to  give  results  disagreeing  as  much  as  tenfold  in  the 
number  of  bacteria  that  would  be  reported  from  any  sample  of  milk.  The  vast 
majority  of  results,  however,  were  much  closer  than  this,  even  at  the  beginning 
of  this  series  of  tests. 

"  7.  After  attention  had  been  called  to  the  points  of  irregularity  and  the  lab- 
oratories had  adopted  methods  of  bringing  about  uniformity  in  technique  so  far 
as  possible,  the  variations  were  very  greatly  reduced,  the  last  tests  showing  that 
when  sufficient  care  is  given  the  variations  need  not  be  more  than  twofold.  It 
is  not  possible  to  rely  upon  a  greater  accuracy  than  100  per  cent,  even  when  an 
average  of  more  than  one  analysis  is  obtained,  although  most  of  the  results  fall 
considerably  below  this  limit. 

"8.  There  is  no  essential  difference  in  the  results  whether  milk  dilution  is 
directly  inoculated  into  the  petri  dish  and  the  agar  poured  upon  it,  or  whether 
the  milk  dilution  is  inoculated  into  the  melted  tube  of  agar  and  subsequently 
poured  into  the  petri  dish.  The  difference  between  the  two  methods  is  so  slight 
as  to  make  it  impossible  to  determine  which  is  the  superior  of  the  two.  But 
when  examinations  of  cream  are  made  the  plate  inoculation  is  unreliable,  and  the 
inoculation  must  be  made  in  the  agar  tube  followed  by  thorough  agitation. 

"9.  Five  days'  incubation  (48  hr.  at  37°  and  72  hr.  at  20°)  gives  a  very 
slightly  greater  count  than  a  2-day  incubation.  The  increase  in  count  is  so  slight 
that  for  general  regulation  purposes  it  is  hardly  superior  to  a  2-day  count;  and 
considering  the  superior  value  of  obtaining  the  count  promptly  there  seems  to  be 
no  reason  for  changing  from  a  2-day  count  to  a  5-day  count. 

"10.  A  24-hr,  count  gives  on  the  average  about  one-half  as  high  numbers  as 
a  48-hr,  count. 

"11.  In  spite  of  all  these  irregularities  the  results  with  duplicate  samples  in 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  443 

the  four  laboratories  have  been  found,  within  certain  somewhat  wide  limits, 
fairly  accurate.  They  are  at  all  events  accurate  enough  to  warrant  three  broad 
grades,  essentially  three  grades  that  have  been  adopted  by  the  commission  on 
milk  standards.  But  they  are  not  as  yet  accurate  enough  to  warrant  a  closer 
grading  than  the  commission's  grades,  A,  B,  and  C,  A  including  all  below  200,000 
(or  100,000),  B  from  200,000  to  1,000,000,  and  C  including  all  above  1,000,000. 
For  this  broad  grading  it  is  necessary  to  have  an  average  of  at  least  four  or  five 
separate  analyses  in  order  to  rely  upon  the  results.  Even  then  there  will  be  an 
occasional  overlapping  of  grade  B  with  either  grade  C  on  the  one  hand  or  grade 
A  on  the  other. 

"12.  This  series  of  tests  has  proved  that  if  a  sample  of  milk  can  be  put  into 
iced  water,  containing  floating  ice,  it  may  be  kept  for  20  hr.  with  very  little  change 
in  bacteria  count.  This  makes  it  possible  to  keep  samples  sent  to  a  laboratory 
for  analysis  for  a  number  of  hours  without  any  fear  of  change  in  bacterial  content, 
provided  the  samples  are  immersed  in  water  containing  floating  ice. 

"13.  These  tests  have  seemed  to  indicate  that  the  American  peptone,  made 
by  the  Digestive  Ferment  Co.,  of  Detroit,  can  be  substituted  for  Witte  peptone 
without  materially  changing  the  results. 

"  14.  Direct  Microscopic  Method  of  Bacterial  Examination  of  Milk  by  the  Breed 
Method. — In  making  a  comparison  of  the  bacteriological  analysis  by  the  plate 
count  and  the  microscopic  count,  the  latter  should  be  a  count  of  groups  rather 
than  individuals,  plate  colonies  representing  groups  only. 

"15.  Considerable  experience  by  the  person  making  the  count  is  needed  to  dis- 
tinguish between  bacteria  and  dirt  particles,  particularly  when  the  milk  contains 
minute  micrococci. 

"16.  When  the  microscopic  count  is  made  by  one  who  has  had  sufficient 
experience,  the  group  count  agrees  somewhat  closely  with  the  plate  count — agree- 
ing, indeed,  about  as  closely  as  the  plate  counts  of  different  laboratories  agree 
with  each  other. 

"17.  Raw,  fresh  milk  does  not  contain  any  appreciable  number  of  dead  bac- 
teria which  might  disclose  themselves  to  the  microscope,  but  fail  to  grow  in  plates . 

"18.  The  direct  microscopical  examination  of  milk  smears  by  the  Breed 
method  will  classify  raw  milk  into  grades  A,  B,  and  C  with  about  the  same  ac- 
curacy and  much  more  quickly  than  the  plate  method  of  bacteriological  analysis 
will  do.  It  is  of  no  use  in  the  study  of  pasteurized  milk,  however,  since  it  dis- 
closes dead  as  well  as  living  bacteria,  no  method  of  distinguishing  between  them 
having  yet  been  perfected.  It  might  be  of  value  in  telling  whether  such  milk  had 
become  old  before  it  was  pasteurized,  since  such  would  show  large  numbers  of 
dead  bacteria  by  the  microscopic  method,  though  it  might  show  small  numbers 
by  the  plate  method. 

"19.  The  direct  microscopical  method  of  bacteriological  analysis  might  be  of 
exceptional  value  applied  at  the  dairy  to  guide  the  dairyman  as  to  the  general 
grade  of  the  milk  he  is  marketing.  It  may  also  be  of  great  aid  to  the  large  dealer 
to  enable  him  to  determine  promptly  whether  he  is  purchasing  milk  of  A,  B,  or 
C  grade.  The  possibility  of  quick  results  and  ease  of  making  the  smears  at  the 
dairy  or  shipping  station,  subsequently  sending  them  to  the  laboratory  for  micro- 
scopic examination,  renders  the  method  especially  applicable  at  the  dairy  end  of 
the  line." 


444  CITY  MILK  SUPPLY 

These  difficulties  in  bacteriological  analysis  are  fully  recognized  and 
competent  analysts  give  them  due  consideration  in  interpreting  results. 
Consequently  objections  to  the  bacterial  count  based  on  these  discrep- 
ancies merely  amount  to  the  charge  that  the  method  is  not  refined  enough 
to  warrant  so  much  stress  being  put  on  its  use.  The  validity  of  this 
accusation,  of  course,  depends  on  the  way  the  analyses  are  interpreted 
and  to  the  uses  they  are  put.  There  is  no  doubt  but  the  attempt  has 
been  made,  particularly  by  untrained  officials,  to  draw  too  fine  distinc- 
tions from  bacteriological  findings  and  it  is  equally  certain  those  who 
know  how  to  use  them  find  them  sufficiently  accurate  to  enable  them  to 
classify  the  milks  of  the  various  dairymen  with  whom  they  are  dealing 
and  to  help  correct  the  shortcomings  of  some  of  them.  But  objections 
to  the  bacterial  count  are  not  limited  to  these  inaccuracies;  it  is  held  by 
some  to  be  irrational,  as  applied  to  raw  milk. 

Some  Factors  That  Should  be  Considered  in  Using  the  Bacterial 
Count. — The  point  is  made  that  it  is  the  kind  of  bacteria,  to  wit,  the  dis- 
ease germs  and  not  the  number  present,  that  is  important  for  it  is  not  only 
possible  but  even  probable  that  in  most  instances  in  which  milks  show 
high  counts  the  microbes  are  perfectly  innocuous  forms  such  as  the  lactic 
acid  germs,  whereas  it  is  conceivable  that  a  milk  carrying  but  few  bacteria 
may  be  infected  with  disease  germs.  To  this  it  is  replied  that  in  the  case 
of  children  there  is  evidence  that  their  tender  intestinal  tracts  may  be 
overwhelmed  by  mere  numbers  of  microorganisms  and  also  that  large 
numbers  of  bacteria  in  milk  indicate  that  it  has  been  produced  under 
filthy  conditions  or  has  been  mishandled. 

When  milk  is  sampled  on  the  farm  and  plated  shortly  thereafter,  the 
bacterial  count  is  within  limits  a  measure  of  the  amount  of  contamination 
the  milk  is  receiving  for  the  germs  are  largely  those  that  are  introduced 
from  fecal  matter,  the  hands  of  the  milker,  the  feed,  the  utensils,  etc., 
but  as  time  lapses  this  is  no  longer  true  for  then  the  bacterial  count  is  the 
result  not  of  a  single  factor  but  of  three,  namely,  of  dirty  dairying,  of 
high  temperature  and  of  age.  It  is  pointed  out  that  in  winter,  or  in 
summer  as  a  result  of  liberal  icing,  the  milk  of  a  dirty  dairyman  may 
compare  favorably,  so  far  as  the  bacterial  count  is  concerned,  with  milk 
produced  by  dairymen  who  are  scrupulously  clean.  Also,  it  is  contended 
that  the  count  so  far  as  it  is  indicative  of  dirt,  does  not  distinguish  be- 
tween human  dirt,  which  is  most  likely  to  be  harmful,  and  animal  dirt, 
which  is  comparatively  harmless.  In  reply  to  these  allegations  it  is 
admitted  that  cold  for  a  longer  or  shorter  time  may  keep  down  the  bac- 
terial counts  of  an  unclean  dairy  to  the  average  of  those  of  clean  ones  but 
it  is  maintained  that  fluctuations  in  the  count  of  the  milk  of  the  dirty 
dairy,  owing  to  failure  to  always  maintain  low  temperatures,  are  bound  to 
occur  with  sufficient  frequency  to  direct  suspicion  to  the  milk  and  ulti- 
mately to  condemn  it.  Furthermore,  it  is  maintained  that  while  it  is 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  445 

true  that  slovenly  dairying,  lack  of  refrigeration  and  age  may  individu- 
ally or  in  combination  produce  high  counts  it  is  not  essential  although  it 
would  be  desirable  to  distinguish  which,  in  any  particular  case,  is  re- 
sponsible for  high  numbers  of  bacteria.  Milk  as  drawn  from  the  udder 
normally  contains  few  bacteria  and  these  are  of  varieties  that  do  not 
multiply  rapidly  in  milk,  consequently  if  it  contains  large  numbers  of 


FIG.  62. — Effect  of  temperature  upon  milk  as  shown  by  bacterial  counts. 

Fig.  1. — Original  sample. 

42°  F.  72°  F. 

After    4  hours Fig.  2  Fig.  5 

After    9  hours Fig.  3  Fig.  6 

After  30  hours Fig.  4  Fig.  7 

(From  the  I4th.  Annual  Report  of  the  Board  of  Health  of  the  Town  of  Montclair,  N.  J.) 

organisms  they  must  originally  have  been  added  in  the  milking  or  after- 
ward and  the  milk  is  abnormal  whether  these  germs  are  the  result  of 
heavy  contamination  at  the  source  or  have  developed  from  a  slight  con- 
tamination because  the  milk  has  been  kept  at  high  temperatures  or 
because  the  milk  is  so  old  or  stale  that  they  have  had  time  to  grow  in  it. 
It  is  the  duty  of  those  regulating  the  supply  to  see  that  milk  as  near 


446  CITY  MILK  SUPPLY 

normal  as  possible  is  marketed.  When  the  sources  of  milk  supply  are 
near  at  hand  and  adequate  refrigeration  is  available,  the  counts  that 
represent  sanitary  production  and  commendable  handling  in  transit 
will  be  lower  than  when  the  sources  of  supply  are  hundreds  of  miles  away 
or  when  dairymen  have  to  contend  with  lack  of  natural  ice,  lack  of  cold 
water  and  high  air  temperatures.  It  might  be  that  part  of  the  milk 
supply  of  a  city  was  produced  under  favorable  conditions  on  farms  in  the 
adjacent  country  and  part  on  equally  good  farms  far  away  so  that  ques- 
tion would  arise  whether  any  bacterial  standard  that  might  be  set  would 
not  be  unjust  for  the  reason  that  the  home  dairies  could  easily  attain  it, 
whereas  it  would  be  both  difficult  and  expensive  for  the  foreign  dairies  to 
do  so.  As  far  as  the  writer  is  aware  such  a  condition  is  unusual  because 
home  dairies  usually  hold  the  market  till  the  high  price  of  farm  land,  etc., 
makes  dairying  unprofitable.  However,  should  there  actually  be  cases 
like  this  suppositious  one,  it  should  not  be  difficult  to  establish  a  standard 
that  will  expose  neither  set  of  dairymen  to  unfair  competition.  The 
outsider  invades  the  local  market,  as  a  rule,  because  he  is  in  a  region  of 
cheap  production.  It  is  only  fair  that  he  be  held  to  local  standards  even 
if  it  is  slightly  more  expensive  for  him  to  meet  them  than  for  the  native 
to  do  so. 

It  is  asserted  that  since  milk  is  consumed  long  before  its  bacterial 
count  is  known,  bacteriological  standards  condemn  the  dairy  and  not 
the  milk  and  that  they  therefore  fail  of  their  object.  If  it  be  admitted 
that  the  intent  of  bacteriological  examinations  is  to  keep  specific  batches 
of  suspected  milk  from  being  consumed  by  the  public,  they  certainly  do 
fail,  but  if  it  is  considered  that  their  object  is  to  prevent  the  habitual 
consumption  of  milk  of  high  bacterial  content,  they  may  be  credited  with 
considerable  success  on  the  testimony  of  the  dealers  in  such  milk  who,  as 
a  rule,  are  the  ones  who  protest  most  vehemently  against  the  publication 
of  bacterial  counts. 

As  to  the  contention  that  bacteriological  examinations  leave  much  to 
be  desired,  in  that  they  fail  to  distinguish  between  animal  contamina- 
tion which  very  rarely  is  the  source  of  the  acute  infections  in  man,  and 
human  contamination  which  often  causes  them,  it  must  be  admitted 
there  is  much  truth.  Still,  the  importance  of  this  defect  is  considerably 
lessened  by  the  fact  that  bovine  tuberculosis  may  be  transmitted  to  milk 
in  the  dung  or  directly  from  the  udder  and  that  septic  sore  throat  though 
primarily  of  human  origin  in  most  of  the  widespread  epidemics  of  the 
disease  has  been  traced  to  udder  infection  and  that  certain  animal  dis- 
eases that  afflict  man  less  commonly  than  these  are  conveyed  in  animal 
secretions  and  excretions. 

Some  disapprove  of  bacterial  standards  because  of  the  difficulty  of 
enforcing  them.  Certainly  any  who  contemplate  establishing  standards 
will  do  well  to  consider  this  point.  In. cases  brought  to  jury  trial  it  is 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  447 

often  hard  to  get  convictions  because  it  is  difficult  to  present  the  subject 
of  bacterial  contamination  of  milk  to  jurors  in  an  intelligible  way.  They 
understand  the  significance  of  skimming,  watering  and  of  the  addition 
of  preservatives  but  bacteria  are  rather  beyond  them  and  they  are  in- 
clined to  think  that  in  selling  milk  of  a  prescribed  bacterial  count  the 
milk  dealer  has  been  guilty  of  violating  a  technical  provision  of  the  code 
of  little  importance  and  accordingly  to  deal  leniently  with  him.  More- 
over, cases  brought  against  dealers  for  violation  of  the  bacterial  standard 
are  apt  to  be  expensive  to  try  for  they  offer  plenty  of  opportunity  for 
the  introduction  of  expert  testimony.  Besides,  although  decisions  have 
been  rendered  that  uphold  bacterial  standards  some  health  officials  doubt 
whether  the  highest  courts  would  sustain  them  and  are  loth  to  make  the 
test.  The  net  result  is  that,  although  many  cities  have  bacterial 
standards,  the  number  of  cases  that  are  brought  for  violating  them  are 
few,  although  milk  that  contains  bacteria  in  excess  of  the  standards  is 
often  sold.  One  reason  for  this,  apart  from  any  question  as  to  the  legality 
or  illegality  of  the  standard,  is  that  it  is  considered  better  policy  to  call 
the  attention  of  dealers  to  the  fact  that  their  milk  violates  the  standard, 
in  the  hope  that  they  will  find  the  cause  and  bring  down  the  count,  than 
it  is  to  prosecute  freely. 

The  question  may  then  be  asked,  of  what  value  are  bacterial  stand- 
ards? They  are  useful  in  that  the  public  sooner  or  later  begins  to  demand 
milk  that  complies  with  the  standards  and  then  the  dealers  begin  to 
furnish  it.  To  do  this  they  have  to  improve  in  their  methods  of  doing 
business  and  it  results  that  boards  of  health  and  other  agencies  take 
part  in  educating  dairymen,  contractors  and  consumers  as  to  how  milk 
should  be  produced  and  cared  for,  with  the  result  that  better  milk  is 
marketed. 

Significance  of  Predominance  of  Acid-forming  and  of  Putrefactive 
Bacteria. — The  better  laboratories  supplement  the  bacterial  count  with 
other  tests  that  are  designed  to  show  the  relative  number  of  lactic,  gas- 
forming  and  putrefactive  bacteria  in  the  milk  and  from  these  determina- 
tions make  certain  tentative  conclusions.  Milks  showing  a  high  percent- 
age of  lactic  organisms  suggest  that  the  milk  may  have  been  produced 
under  cleanly  conditions  but  that  there  has  been  time  for  these  organisms 
to  grow,  or  that  possibly  the  utensils  are  not  kept  clean  and  sterile. 
Large  numbers  of  gas-forming  and  putrefactive  bacteria  are  indicative 
of  dirty  methods.  Similarly,  other  tests  are  used  and  deductions  made 
from  them.  Such  tests  often  enable  inspectors  to  economize  time  by 
indicating  the  probable  source  of  trouble  that  they  are  sent  out  to  help 
some  farmer  find  and  eliminate. 

Significance  of  the  Streptococci. — Besides  using  the  bacterial  count 
in  controlling  the  milk  supply  it  has  been  proposed  to  use  other  bacterio- 
logical tests  as  a  basis  for  excluding  milk  from  the  market. 


448  CITY  MILK  SUPPLY 

In  many  laboratories  the  presence  in  milk  of  streptococci  forming 
chains  in  lactose  broth  at  98.6°F.  is  accepted  as  evidence  that  the  milk 
or  a  part  of  it  was  from  infected  udders  and  some  hold  that  it  proves  the 
milk  polluted  with  cow  dung.  Rogers,  Clark  and  Evans  have  investi- 
gated the  validity  of  the  test.  They  studied  51  cultures  from  two  herds 
in  which  infected  udders  had  given  trouble  and  found  that  the  cultures 
could  be  divided  into  two  varieties  which  were  related  but  which  were 
separated  by  certain  distinctive  characters.  Nearly  all  cultures  of 
both  types  fermented  lactose,  saccharose  and  dextrose  and  failed  to  fer- 
ment raffinose,  starch  and  inulin  but  the  more  numerous  type  which  had 
a  marked  tendency  to  form  long  chains  in  broth  at  98.6°F.  failed  to  fer- 
ment mannit  and  glycerine  and  to  liquefy  gelatin,  whereas  the  other 
type  nearly  always  did  so.  The  type  with  the  tendency  to  form  long 
chains  corresponds  to  St.  pyogenes  as  regards  the  reactions  that  have 
been  considered.  A  study  of  114  cultures  of  streptococci  isolated  from 
bovine  feces  showed  they  differed  from  the  long-chain  type  in  the  amount 
of  acid  produced  and  in  the  substances  fermented,  for  besides  fermenting 
dextrose,  saccharose  and  lactose,  they  almost  always  fermented  raffinose, 
while  about  50  per  cent,  of  them  fermented  starch  and  a  few  inulin  but 
they  were  unable  to  utilize  the  alcohols  except  that  a  few  fermented 
mannit.  From  this  work  and  the  study  of  42  cultures  isolated  from 
milk  from  25  farms  by  inoculating  lactose  bile,  incubating  at  98.6°F. 
and  plating  only  those  tubes  showing  distinct  chains,  the  authors  make 
the  statement  that,  while  their  results  are  not  conclusive,  they  hold 
them  as  substantiating  the  belief  that  the  presence  in  lactose  bile,  inocu- 
lated with  milk  and  incubated  at  98.6°F.,  of  chain-forming  streptococci 
is  good  presumptive  evidence  of  milk  from  infected  udders.  They  point 
out,  however,  that  udders  may  contain  streptococci  of  the  pyogenes 
type  without  showing  physical  signs  of  infection. 

Significance  of  B.  coli. — In  water  analysis  the  presence  of  the  colon 
bacillus  is  regarded  as  indicative  of  fecal  pollution  because  the  organism 
is  a  normal  inhabitant  of  the  intestines  of  man  and  of  the  lower  animals 
and  for  the  same  reason  some  health  departments  have  endeavored  to 
make  the  presence  of  excessive  numbers  of  these  bacteria  in  milk  a  reason 
for  excluding  it  from  the  market.  This  has  excited  vigorous  protest 
on  the  grounds  that  these  germs  multiply  rapidly  in  milk  which  they  do 
not  in  water,  and  that  the  studies  of  Prescott  and  others  show  that  organ- 
isms of  the  colon  group  are  found  not  only  in  feces  but  also  on  grains 
which  are  commonly  used  as  cattle  feed. 

The  feasibility  of  using  this  test  has  been  investigated  by  Rogers, 
Clark  and  Evans.  They  began  their  investigation  with  a  study  of  120 
cultures  from  milk  samples  taken  in  various  parts  of  the  country.  It 
was  found  possible  to  divide  these  cultures  into  two  groups  on  the  basis 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  449 

of  the  ratio  of  carbon  dioxid  to  hydrogen  in  the  gas  produced  in  the  fer- 
mentative reactions  that  were  studied.  One  of  these  two  groups  had  a 
carbon  dioxid  ratio  of  1:1  and  was  designated  as  the  low-ratio  group. 
The  other  group  had  a  higher  ratio.  The  correlation  of  other  characters 
with  these  types  of  gas  ratio  was  sufficiently  marked  to  make  the  separa- 
tion of  the  two  groups  clear  and  distinct.  To  determine  whether  both 
groups  were  normal  inhabitants  of  the  intestine  a  study  was  made  of  150 
cultures  from  bovine  feces.  It  was  found  that  149  of  them  gave  the  1:1" 
ratio  which  characterized  about  50  per  cent,  of  the  120  milk  cultures.  The 
single,  high-ratio  culture  was  distinguished  by  a  yellow  pigment.  ,  The"" 
fermentative  reactions  that  were  studied  confirmed  the  agreefhent  be- 
tween the  feces  organisms  and  the  low-ratio  milk  cultures.  Further 
studies  showed  that  the  entire  low-ratio  group  is  divided  into  two  sub- 
groups corresponding  to  B.  coli  communis  and  B.  coli  communior.  To 
determine  whether  the  colon  bacillus  occurs  elsewhere  than  in  the  intes- 
tine a  study  was  made  of  166  cultures  from  33  samples  of  common  grains. 
Nearly  all  of  these  cultures  responded  to  presumptive  tests  for  B.  coif 
and  many  would  have  passed  the  usual  confirmatory  tests.  On  the  basis 
of  gas  ratio  the  grain  cultures  were  separable  into  three  groups,  viz.: 
(1)  eight  of  the  cultures  had  the  characteristic  colon  ratio;  (2)  a  group 
that  produced  only  carbon  dioxid  and  so  had  a  ratio  equal  to  infinity; 
(3)  a  group  that  gave  gas  ratios  varying  from  1.90  to  2.90.  In  the  166 
cultures  a  number  of  pigment  formers  were  noticed  and  so  the  cultures 
were  matched  with  Ridgew"ay's  standard  color  plates  whereby  it  was 
demonstrated  that  a  larger  proportion  of  the  cultures  formed  pigment  to 
some  extent.  However,  the  amount  was  so  small  in  most  cases  that  the 
culture  would  not  ordinarily  be  considered  pigmented.  Among  the  de- 
cidedly colored  cultures  were  all  those  that  gave  the  colon  ratio  of  1:1. 
In  all  cases  the  color  varied  from  a  cadmium  yellow  to  cream  color  or 
nearly  white.  The  153  cultures  that  gave  a  high  ratio  were  divided  by 
the  authors  into  five  groups. 

Therefore,  the  entire  collection  was  divided  into  six  groups;  one  of 
them  included  40  cultures  and  another  90,  and  in  these  the  uniformity  of 
reaction  was  striking.  The  number  of  cultures  in  the  other  groups  was 
so  small  as  to  make  the  groups  little  more  than  suggestions. 

The  authors  conclude  that  the  bacteria  of  the  colon  type  occurring 
in  market  milk  may  be  divided  into  two  distinct  groups  one  of  which  is 
characterized  by  a  low  carbon  dioxid  ratio  that  is  typical  of  the  colon 
bacillus  of  the  bovine  intestine.  The  other,  or  high-ratio  group,  is 
numerous  in  milk  but  occurs  only  rarely  in  the  bovine  intestine.  The 
surface  of  dried  grains  is  the  source  of  a  number  of  types  of  colon' but 
only  one  of  them  resembles  the  low-ratio  feces  type  and  this  one  is  dis- 
tinguished by  its  ability  to  form  pigment.  Of  the  cultures  from  grains 
the  type  that  is  most  common  probably  corresponds  to  Baet.  lactis 

v 


450  CITY  MILK  SUPPLY 

aerogenes.  However,  many  grain  cultures  would  answer  to  the  usual 
tests  for  B.  coli  communis  and  B.  coli  communior. 

While  the  presence  of  fecal  bacteria  in  milk  may  be  determined  with 
great  certainty  the  ordinary  presumptive  tests  and  even  the  usual 
confirmatory  ones  do  not  necessarily  prove  the  contamination  of  milk 
with  fecal  matter. 

Significance  of  B.  welchii. — Savage  has  pointed  out  that  the  spores  of 
B.  welchii  are  present  in  cow  dung  in  considerable  numbers  and  has 
suggested  that  since  the  organism  does  not  multiply  in  milk  it  might  be 
used  as  an  index  of  animal  contamination  of  market  milk.  However, 
he  mentions  the  fact  that  it  is  not  known  how  far  the  organism  may  gain 
entrance  to  the  milk  from  other  sources  than  manure. 

Bacterial  Tests  of  Pasteurized  Milk. — In  the  examination  of  pas- 
teurized milk,  bacteriological  tests  are  considered  of  great  value.  They 
are  used  to  test  the  sterility  of  the  apparatus  before  starting  a  run  and 
by  taking  samples  of  the  milk  at  different  stages  of  its  journey  through 
the  machines  to  determine  the  places  where  defects  occur.  The  finished 
product  should  meet  reasonable  bacteriological  standards,  if  the  pasteur- 
ization has  been  successful.  In  some  cities  a  certain  percentage  reduc- 
tion in  bacteria  is  required.  The  fallacy  in  this  standard  has  been  pointed 
out  in  the  chapter  on  pasteurization.  The  best  way  is  to  forbid  the 
pasteurization  of  milk  that  has  a  bacterial  content  in  excess  of  a  stated 
amount  and  to  require  that  the  pasteurized  milk  shall  not  contain  over  a 
stated  number  of  bacteria  per  cubic  centimeter. 

In  some  cities  the  colon  test  is  used  as  an  index  of  the  efficiency  of 
pasteurization.  Of  this  Ayers  and  Johnson  say  that  it  is  complicated  by 
the  ability  of  certain  strains  to  survive  a  temperature  of  145°F.  for  30 
min.  and  to  develop  rapidly  when  pasteurized  milk  is  held  under  tem- 
perature conditions  that  might  be  met  during  storage  and  delivery. 
The  presence  of  a  large  number  of  colon  bacilli  right  after  the  heating 
process  may  indicate  improper  treatment  of  the  milk.  Milk  pasteurized 
at  150°F.  or  above  for  30  min.,  according  to  the  researches  of  these 
authors,  would  not  contain  colon  bacilli  but  they  emphasize  the  fact  that 
more  extensive  work  might  reveal  strains  of  colon  bacilli  that  would 
survive  this  and  even  higher  temperatures. 

Prevention  of  Milk-borne  Epidemics. — Besides  keeping  up  the  sani- 
tary condition  of  places  where  milk  is  produced,  handled  and  sold,  by 
inspecting  and  scouring  them,  and  besides  maintaining  the  quality  of  the 
supply  by  laboratory  work,  it  is  necessary  to  make  a  systematic  effort 
to  protect  the  milk  from  infection  and  to  prevent  it  becoming  the  vehicle 
of  contagion.  This  work  usually  receives  the  personal  attention  of  the 
health  officer.  In  the  larger  cities  a  staff  of  specially  trained  men  deals 
with  communicable  diseases  and  usually  cooperates  with  the  bureau  of 
milk  inspection  in  carrying  on  that  part  of  the  work  which  pertains  to 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  451 

the  milk  supply.  In  the  smaller  cities  the  health  officer  and  members  of 
the  milk  inspection  service  do  it  all. 

The  work  is  naturally  divided  into  two  parts:  that  which  is  done  in 
the  country  districts,  usually  within  the  sphere  of  authority  of  some  other 
official,  perhaps  a  county  health  officer;  and  that  which  is  carried  on  in 
the  city  where  the  municipal  health  officer  has  sole  jurisdiction.  The 
first  step  is  to  see  that  all  cases  of  infectious  disease  of  men  and  animals 
are  promptly  reported.  As  regards  the  latter,  veterinarians  usually 
willingly  give  helpful  service,  and  cooperation  in  handling  the  cases  is 
generally  mutually  advantageous.  The  reporting  of  cases  of  human 
contagion  on  the  dairy  farms  and  among  the  patrons  and  employees  of 
the  creameries,  country  and  city  milk  plants,  etc.,  should  be  incumbent  on 
the  dairymen  and  contractors  who  sell  their  milk  or  own  the  factories. 
Besides,  arrangements  should  be  made  with  the  local  physicians  and 
health  officer  to  report  all  cases  of  infection  in  the  dairy  district  and  with 
the  registrar,  to  report  all  deaths  from  contagion.  It  is  for  the  municipal 
health  officer  to  see  that  all  cases  of  communicable  disease  in  the  city  are 
promptly  reported  and  that  in  each  report  the  name  of  the  milk  dealer 
is  given. 

For  collecting  and  recording  this  and  other  data  relating  to  communi- 
cable diseases  suitable  blanks  and  a  system  of  office  records  should  be 
devised.  All  cases  of  contagion  should  be  spotted  on  a  large  map  of  the 
city.  This  gives  a  general  view  of  the  amount  of  infection  and  shows 
the  relative  prevalence  of  the  several  diseases.  Oftentimes,  too,  the 
groupings  of  the  cases  on  the  map  are  suggestive  of  epidemiological  re- 
lationships. Thus,  if  the  spots  are  scattered  in  all  parts  of  the  city  where 
the  public  water  supply  is  used,  the  suspicion  is  aroused  that  the  water  is 
infected  and  this  seems  more  certain  if  no  spots  appear  in  a  section  of  the 
city  not  served  by  the  public  supply.  A  row  of  spots  along  a  line  of  sewer 
pipe  may  indicate  that  it  is  leaky  and  is  polluting  the  wells  in  the  street 
in  which  it  is  laid.  Sometimes  the  spots  may  be  disposed  about  a  well 
in  such  a  way  that  near  it,  they  may  be  close  together  but  further  away 
spread  apart  and  at  a  greater  distance  disappear.  A  circle  of  short  radius 
and  with  the  well  as  a  center  will  circumscribe  all  the  cases  which  denotes 
that  the  neighborhood  is  using  the  water  of  an  infected  well.  If  the  spots 
mark  out  the  delivery  route  of  a  milk  dealer,  the  probability  is  that  his 
milk  is  infected.  In  the  case  of  an  infected  route  that  is  generally  patron- 
ized the  spots  may  be  so  broadly  scattered  that  doubt  is  cast  on  the 
purity  of  the  public  water  supply  but  careful  inquiry  will  dispel  it.  Other 
groupings  have  their  proper  interpretations.  Also,  the  city  should  be 
divided  into  several  fairly  large  districts  which  should  be  kept  intact 
from  year  to  year  and  the  occurrence  of  cases  of  contagion  in  them  should 
be  noted  for  careful  study.  Thus,  the  cases  of  contagion  should  be  re- 
corded as  they  occur  week  by  week  throughout  the  year  over  a  series 


452  CITY  MILK  SUPPLY 

of  years  and  from  this  should  be  figured  the  average  number,  or  the  normal 
incidence  of  cases,  in  each  district  in  each  of  the  52  weeks  so  that  at  any 
time  that  may  be  necessary  it  may  be  quickly  told  whether  there  are  more 
cases  than  normal  for  that  week. 

Each  case  of  infection,  as  it  occurs,  should  be  charged  to  the  dealer 
who  happens  to  be  serving  the  patient  with  milk.  This  should  be 
done  not  with  the  idea  of  fixing  the  responsibility  for  the  case  on  the  dealer 
but  rather  to  discover  the  occurrence  of  any  unusual  number  of  cases 
among  the  dealer's  customers.  If  the  number  of  cases  appears  to  be 
excessive,  care  should  be  taken  to  ascertain  whether  it  really  is  so,  by 
figuring  whether  the  proportion  of  all  the  cases  in  the  city  that  he  is  get- 
ting corresponds  to  the  size  of  his  milk  route  or  not. 

In  some  cities  dairymen  are  required  to  file  lists  of  their  customers 
with  the  board  of  health  at  stated  intervals.  This  gives  information  as 
to  the  size  and  location  of  the  route  and  is  sometimes  convenient  in 
checking  up  statements  of  patients  as  to  the  milk  they  were  using  when 
they  were  stricken  with  disease. 

It  is  highly  important  to  be  able  to  trace  milk  back  to  the  producer 
with  celerity  and  certainty.  So  there  must  be  some  way  of  recording  the 
point  of  origin  of  each  shipment  of  milk.  In  New  York  City  the  Depart- 
ment of  Health  requires  that  to  each  can  of  milk  there  be  attached  a  tag 
showing  where  the  milk  was  shipped  from  and  the  date  of  shipment.  The 
milk  companies  are  also  required  to  keep  a  record  of  the  distribution 
of  this  milk  to  the  various  retailers.  Bottled  milk  must  be  dated  and 
be  marked  with  the  name  of  the  creamery  or  bottling  plant  and  the 
records  of  the  companies  must  show  on  what  wagons  and  routes  milk 
bottled  in  the  country  is  distributed.  Retail  dealers  are  required  to 
keep  the  can  tags  for  60  days. 

It  is  important  to  have  some  routine  way  of  notifying  the  dairyman 
of  the  occurrence  of  cases  of  contagion  on  his  route,  otherwise  he  is  likely 
to  violate  the  provisions  of  the  code  relative  to  taking  away  bottles  from 
infected  homes.  Epidemics  have  been  caused  in  this  way.  If  bottles 
are  left  daily  at  infected  premises  and  not  taken  away  until  the  case  is 
over,  a  considerable  number  accumulate  and  there  is  some  possibility  of 
their  infecting  the  dairy  or  of  their  being  put  into  circulation  without 
proper  sterilization.  The  danger  is  greatest  when  the  dairyman  is  not 
very  intelligent  and  when,  as  is  often  the  case  in  small  cities,  he  lacks 
facilities  for  sterilizing.  In  such  cases  the  board  of  health  should  sterilize 
the  bottles  with  bleaching  powder  before  they  are  taken  from  the  premises. 

There  is  a  further  point  to  be  considered  in  controlling  the  spread  of 
contagious  disease  through  milk  and  it  is  pertinent  to  other  phases  of 
milk  regulation  as  well.  It  is,  as  to  how  to  prevent  milk  that  is  excluded 
from  one  town  finding  market  in  another.  That  this  often  happens  there 
is  no  doubt.  Sometimes  it  can  be  prevented  by  notifying  a  State  depart- 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  453 

ment  of  milk  control  of  the  exclusion  but  often  there  is  no  such  board 
with  authority  or  the  resources  to  prevent  the  shipment  of  the  milk. 
Generally  the  best  plan  of  protection  is  for  neighboring  communities 
to  adopt  an  arrangement  for  promptly  notifying  each  other  of  the  exclu- 
sion of  any  dairy  from  one  of  the  cities.  Some  go  further  and  exchange 
their  weekly  reports  upon  communicable  disease. 

Methods  of  Maintaining  Public  Interest  in  the  Milk  Supply. — These 
are  the  principal  lines  along  which  efforts  at  milk  control  are  directed. 
There  remain  to  be  considered  means  of  maintaining  interest  in  the  milk 
situation  and  of  making  the  milk  inspection  bureau  serviceable  to  the 
community.  Carefully  considered  and  well-directed  publicity  is  the 
agent  for  accomplishing  these  things.  Newspapers  generally  gladly 
assist  temperate  constructive  campaigns  for  improving  the  milk  supply. 
The  rural  press  will  usually  accept  short  articles  on  such  subjects  as 
cow-testing  associations,  bull  associations,  the  handling  of  manure, 
feeding,  the  production  of  clean  milk  and  the  like.  Often  country  and 
city  papers  will  publish  dairy  scores.  In  a  community  where  control 
work  is  new  it  is  well  to  begin  with  publishing  only  the  good  scores.  This 
excites  the  interest  of  the  farmers  and  is  an  incentive  to  those  whose 
places  are  in  poor  condition  to  improve  them.  Ultimately  the  scores 
of  all  the  farms  can  be  published.  The  question  of  whether  chemical 
and  bacteriological  milk  analyses  should  be  published  and  the  supplies 
of  all  the  dealers  rated  has  excited  discussion.  The  first  question  that 
presents  itself  is  whether  the  publication  of  analyses  is  legal;  in  com- 
munities where  it  is  not,  the  matter  is  ended.  Those  who  oppose  publish- 
ing analyses  contend  that  to  do  so  is  unfair  to  the  dealer  because  the  con- 
sumers are  unable  to  understand  them  and  so  are  confused  and  often 
misled  by  them.  Those  who  would  publish  analyses  feel  that  the  public 
pays  for  all  the  analytical  work  and  so  is  entitled  to  know  how  the  different 
supplies  may  be  judged  in  accordance  with  it.  Montclair,  N.  J.,  and 
other  cities  have  long  published  both  the  chemical  and  bacteriological 
analyses  of  the  milk  of  all  the  dealers  in  their  annual  reports.  This  by 
many  is  considered  fair  because  it  shows  the  general  character  of  the 
supplies  over  a  considerable  period  of  time.  Others  regard  this  as  stale 
news  and  believe  that  few  consumers  use  it.  This  latter  criticism  cer- 
tainly is  not  valid  in  Montclair.  In  some  cities  the  analyses  are  published 
in  the  daily  press  right  after  they  are  made.  The  objection  to  this  is 
that  an  opinion  in  regard  to  a  milk  supply  should  never  be  formed  on  a 
single  analysis  and  that  in  the  best-managed  dairies  accidents  will  happen 
that  might  cause  an  occasional  analysis  to  misrepresent  completely  the 
real  character  of  the  supply.  It  is  truly  held  that  the  regular  publication 
of  analyses  makes  it  unnecessary  to  adopt  a  bacterial  standard  because 
dealers  will  strive  to  get  lower  counts  than  their  competitors  and  so  milks 
with  high  counts  will  gradually  decrease  in  number  and  the  average  maxi- 


454 


CITY  MILK  SUPPLY 


mum  count  grow  lower.  The  tendency  of  consumers  to  select  milk  with 
low  counts  acts  in  the  same  way.  Many  believe  that  the  publication  of 
analyses  makes  the  marketing  of  good  milk  profitable.  Some  take  the 
rather  doubtful  ground  that  the  board  has  done  its  duty  when  it  makes 
known  the  quality  of  the  various  milks  on  the  market  and  that  it  is  then 


FIG.  63. — Bacteria  in  the  same  quantity  of  milk  from  different  sources. 

Fig.  1. — Exceptionally  pure  milk. 

Fig.  2. — Blauyelt,  Geo.  M.  Canfield,  Fairfield  certified. 
Fig.  3. — Hamilton,  Fairfield  Nursery,  Van  Reyper. 
Fig.  4. — Puritan  Dairy,  Offhouse. 
Fig.  5. — Croot,  Borden  M.  H.  Canfield,  O'  Dowd. 
Fig.  6. — Dirty  milk. 
(From  the  14th.  Annual  Report  of  the  Board  of  Health  of  the  Town  of  Montclair,  N.  J.) 

the  public's  own  fault  if  it  uses  the  inferior  ones.  Others  feel  that  it  is 
the  duty  of  the  board  to  protect  the  public  from  the  folly  of  choosing  the 
poorer  milks.  Many  argue  that  the  publication  of  scores  and  analyses  is 
an  ineffective  way  of  getting  good  results,  that  these  should  be  employed 
to  the  benefit  of  the  public  and  dealers  by  using  them  in  grading  the  milk. 
This  seems  to  be  the  opinion  of  the  Committee  of  the  International  Milk 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  455 

Dealers'  Association  on  the  Improvement  of  Milk  Supplies  for  it  recom- 
mends that  milk  dealers  urge  upon  boards  of  health  in  their  respective 
cities  the  establishment  and  supervision  of  grades  of  milk  and  it  advises 
the  adoption,  with  such  modifications  as  local  conditions  may  suggest, 
of  the  grades  defined  by  the  Commission  appointed  by  the  New  York  Milk 
Committee.  Pending  the  establishment  of  grades  of  milk  the  Committee 
of  the  Milk  Dealers'  Association  advises  that  dealers  urge  upon  boards 
of  health  the  publication  of  both  chemical  and  bacteriological  analyses 
or  the  publication  of  the  scores  of  the  various  supplies  distributed,  as  in 
effect  in  Seattle. 

In  these  Seattle  classified  milk  scores  100  points  are  allowed  for  the 
dairy  farm,  100  for  chemical  analysis,  and  100  for  bacteriological  analysis, 
making  a  total  of  300  possible  in  the  perfect  score,  and  the  percentage 
that  the  total  number  of  points  actually  scored  is  of  the  total  possible 
score  gives  the  final  rating.  The  dairy  farm  is  scored  according  to  the 
"official"  score  card.  The  chemical  and  bacteriological  analyses  are 
scored  in  accordance  with  values  assigned  on  the  U.  S.  Department  of 
Agriculture  score  card  for  milk. 

So,  if  a  milk  was  produced  on  a  farm  that  was  scored  59  points  and 
if  the  chemical  analysis  showed  that  it  contained  12.89  total  solids  enti- 
tling it  to  90  points  and  if  its  bacterial  count  was  84,000  giving  it  60 
points,  its  final  rating  would  be  the  sum  of  these  points  or  209  divided 
by  300  or  69.6  per  cent. 

A  more  highly  elaborated  system  of  rating  was  devised  by  Woodward 
for  use  in  Washington,  D.  C. 

The  interest  of  producers,  milk-plant  managers  and  dealers  is  stimu- 
lated by  calling  meetings  at  which  opportunity  is  given  them  to  discuss 
their  difficulties  and  to  make  suggestions  with  regard  to  the  administra- 
tion of  the  milk  code.  It  is  particularly  important  in  drawing  up  a  new 
code  or  in  amending  an  old  one  that  these  men  be  called  into  consultation. 
Their  intimate  knowledge  of  the  local  situation  and  their  practical  ex- 
perience, if  availed  of,  will  prevent  the  incorporation  of  unworkable 
provisions  into  the  law  and  the  adoption  of  a  code  so  far  beyond  the 
ability  of  the  industry  to  live  up  to  that  it  will  be  a  failure  from  the  date 
of  its  enactment.  Besides  this,  the  spirit  of  fair  play  demands  that  the 
men  whose  business  is  to  be  regulated  should  have  ample  opportunity  to 
present  objections  and  suggestions  in  regard  to  the  proposed  legislation. 
Too  often  half-informed  committees  and  legislative  bodies  have  imposed 
impossible  laws  on  the  dairy  business  to  the  detriment  of  all  concerned. 

The  good  will  and  support  of  the  producers  can  be  won  by  helping 
them  to  establish  cow-testing  associations,  bull  associations  and  other 
things  calculated  to  advance  their  prosperity. 

The  effort  should  be  made  to  develop  the  habit  of  reading  and  study 
in  the  dairymen.  To  this  end  the  bulletins  of  the  various  experiment 


456 


CITY  MILK  SUPPLY 


stations  and  of  the  Federal  Government  should  be  distributed  among 
them  and  a  loan  library  of  such  literature  as  cannot  be  given  away  should 
be  kept  in  the  department. 

One  of  the  problems  that  the  bureau  of  control  has  to  meet  is  how  to 
make  the  community  as  a  whole  respond  to  its  work.  Unless  the  citizens 
can  be  interested  in  the  milk  question  and  be  made  participants  in  the 
movement  to  improve  the  milk  supply  and  unless  they  can  be  made  to 
feel  that  they  are  being  benefited  in  a  practical  way,  no  lasting  results 
can  be  obtained.  Therefore,  the  effort  must  be  made  to  carry  the  work 
to  the  public.  Usually  there  is  opportunity  to  do  this  through  the 
medium  of  lectures  before  women's  clubs,  granges,  fraternal  orders  and 
church  societies.  In  some  cases  the  public  schools  can  be  induced  to 
give  some  instruction  on  milk.  If  there  is  a  domestic  science  depart- 
ment in  the  high  school,  its  head  is  usually  very  glad  to  utilize  material 
furnished  by  the  control  bureau  and  may  even  arrange  trips  to  dairies 
and  milk  plants. 

UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 

Bureau  of  Animal  Industry 

Dairy  Division 


SCORE  CARD  FOR  MILK 

(Front) 


Class  Exhibit  No  

Item 

Perfect 
score 

Score 
allowed 

Remarks 

Bacteria  

35 

25 

10 
10 
10 
5 

5 

Bacteria  found  per  ) 

Flavor  and  odor 

cubic  centimeter  / 
Cowy,  Bitter,  Feed,  \ 

Visible  dirt 

Flat,  Strong,            J 

Fat  



Per  cent,  found  

Solids-not-fat 

Per  cent,  found     , 

Acidity 

Per  cent  found                       

Bottle  and  cap  ; 

f  Cap  

\  Bottle  

Total  

100 

Exhibitor 

Address 

(Signed) . 

Date.. 


Judge. 


,  191 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


457 


Sometimes  it  is  possible  to  set  up  a  milk  booth  at  some  local  bazaar 
or  even  to  organize  a  milk  show  at  which  lectures  are  given,  lantern 
slides  or  moving  pictures  of  the  local  dairies  are  exhibited  and  perhaps  a 
milk  and  cream  contest,  with  prizes  for  the  best  milk,  is  staged.  The 
object  of  these  contests  is  twofold.  First,  the  dairymen  who  enter  the 
contest  learn  a  great  deal  in  a  practical  way  about  sanitary  milk  produc- 
tion and  this  lesson  is  never  unlearned.  Besides,  the  success  of  the  prize 
winners  whets  the  ambition  of  others  so  that  they  bestir  themselves  to 
do  better.  Second,  the  public  is  always  interested  in  a  contest  and  a 
successfully  managed  competition  always  excites  lively  discussion  of  all 
phases  of  the  milk  question.  The  judges  should  be  selected  with  care  and 
the  milk  and  cream  should  be  scored  on  the  cards  of  the  U.  S.  Department 
of  Agriculture,  facsimiles  of  which  appear  on  pages  456,  457  and  458. 

SCORE  CARD  FOR  MILK 

(Back) 


DIRECTIONS  FOR  SCORING 


Bacteria  per  Cubic  Centimeter — Perfect  Score,  35 

Points 

Under  500 35.0 

500-  1,000 

1,001-  1,500 

1,501-  2,000 34.7 

2,001-  2,500 34.6 

,    2,501-  3,000 34, 

3,001-  3,500 34 

3,501-  4,000 34. 

4,001-  5,000 34, 

5,001-  6,000 33, 

6,001-  7,000 33. 

7,001-  8,000 33. 

8,001-  9,000 33, 

9,001-10,000 33. 

10,001-11,000 32. 

11,001-12,000 32. 

12,001-13,000 32. 

13,001-14,000 32. 

14,001-15,000 32. 

15,001-20,000 31 . 

20,001-25,000 30. 

NOTE. — When  the  number  of  bacteria  per  cubic  centimeter  exceeds  the  local  legal 
limit  the  score  shall  be  0. 

Flavor  and  Odor— Perfect  Score,  25 

Deductions  for  disagreeable  or  foreign  odor  or  flavor  should  be  made  according  to 
conditions  found.  When  possible  to  recognize  the  cause  of  the  difficulty  it  should 
be  described  under  Remarks. 


ints 

0 

25,001-  30,000 

Points 

29  0 

.9 

8 

30,001-  35,000  
35,001-  40,000 

28.0 
27  0 

.7 
6 

40,001-  45,000  
45,001-  50,000.  ... 

26.0 
25  0 

6 

50,001-  55,000 

24  0 

.4 
3 

55,001-  60,000  
60,001-  65,000 

23.0 
22  0 

.0 

65,001-  70,000  

21  0 

8 

70,001-  75,000     . 

20  0 

.6 

75,001-  80,000  

19  0 

4 

80,001-  85,000. 

18  0 

.2 
.0 

85,001-  90,000  
90,001-  95,000  

17.0 
16  0 

8 

95,001-100,000 

15  0 

.6 

100,001-120,000  .    . 

12  5 

4 

120,001-140,000 

10  0 

.2 

140,001-160,000  

7  5 

0 

160,001-180,000 

5  0 

.0 

180,001-200,000  

2.5 

.0 

Above    200,000.. 

0.0 

458 


CITY  MILK  SUPPLY 


Visible  Dirt — Perfect  Score,  10 

Examination  for  visible  dirt  should  be  made  only  after  the  milk  has  stood  for  some 
time  undisturbed  in  any  way.  Raise  the  bottle  carefully  in  its  natural,  upright 
position,  without  tipping,  until  higher  than  the  head.  Observe  the  bottom  of  the  milk 
with  the  naked  eye  or  by  the  aid  of  a  reading  glass.  The  presence  of  the  slightest 
movable  speck  makes  a  perfect  score  impossible.  Further  deductions  should  be  made 
according  to  the  amount  of  dirt  found.  When  possible  the  nature  of  the  dirt  should 
be  described  under  Remarks. 


Fat  in  Milk— Perfect  Score,  10 


Points 

4.0  per  cent,  and  over 10.0 

3 . 9  per  cent 9.8 

3 . 8  per  cent 9.6 

3 . 7  per  cent 9.4 

3. 6  per  cent 9.2 

3 . 5  per  cent 9.0 

3. 4  per  cent 8.0 

3. 3  per  cent 7.0 


Points 

3. 2  per  cent 6 

3 . 1  per  cent 5 

3 . 0  per  cent 4 

2. 9  per  cent 3 

2 . 8  per  cent 2 

2 . 7  per  cent 1 

Less  than  2 . 7  per  cent 0 


NOTE. — When  the  per  cent,  of  fat  is  less  than  the  local  legal  limit  the  score  shall 
be  0. 


Solids -not-Fat — Perfect  Score,  10 


Points 

8 . 7  per  cent,  and  over 10 

8 . 6  per  cent 9 

8 . 5  per  cent 8 

8 . 4  per  cent 7 

8 . 3  per  cent 6 

8 . 2  per  cent 5 


Points 

8. 1  per  cent 4 

8 . 0  per  cent 3 

7 . 9  per  cent 2 

7 . 8  per  cent 1 

Less  than  7 . 8  per  cent 0 


NOTE. — When  the  per  cent,  of  solids-not-fat  is  less  than  the  local  legal  limit  the 
score  card  shall  be  0. 


Acidity — Perfect  Score,  6 

Points 

0 . 2  per  cent,  and  less 5 

0 . 21  per  cent 4 

0 . 22  per  cent 3 


Points 

0.23  per  cent 2 

0.24  per  cent 1 

Over  0.24  per  cent 0 


Bottle  and  Cap — Perfect  Score,  5 

Bottles  should  be  made  of  clear  glass  and  free  from  attached  metal  parts.  Caps 
should  be  sealed  in  their  place  with  hot  paraffin,  or  both  cap  and  top  of  bottle  covered 
with  parchment  paper  or  other  protection  against  water  and  dirt.  Deduct  for  tinted 
glass,  attached  metal  parts,  unprotected  or  leaky  caps,  partially  filled  bottles,  or 
other  conditions  permitting  contamination  of  milk  or  detracting  from  the  appearance 
of  the  package. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


459 


UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 
Bureau  of  Animal  Industry 
Dairy  Division 


SCORE  CARD  FOR  CREAM 


Place 

Class.  .  .   Exhibit  No. 


Item 

Perfect 
score 

Score 
allowed 

Remarks 

Bacteria 

35 

Bacteria  found  per 

Flavor  and  odor  
Visible  dirt 

25 
10 



cubic  centimeter 
Cowy,  Bitter,  Feed,  \ 
Flat,  Strong, 

Fat  .  .                       ... 

20 

Per  cent,  found     

Acidity 

5 

Per  cerit  found                 

f  -Cap 

Bottle  and  cap  

5 

\  Bottle. 

Total 

100 



Exhibitor 


Address 


(Signed) 


Judge. 


Date ,  191 

The  directions  for  scoring  are  the  same  as  for  milk. 


Measures  of  Success  in  Controlling  the  Milk  Supply. — The  success 
of  the  effort  to  control  the  production  and  sale  of  milk  is  measured  in 
three  ways,  namely:  (1)  by  the  decrease  in  infant  mortality;  (2)  by  the 
increase  in  the  consumption  of  milk;  and  (3)  by  the  prosperity  of  the 
dairy  business. 

Infant  Mortality  and  the  Milk  Supply. — Undoubtedly  the  belief  of 
the  medical  profession  that  contaminated  milk  was  largely  responsible 
for  the  high  infant  mortality  of  the  summer  months  started  the  first 
comprehensive  campaigns  to  improve  milk  supplies.  In  the  seventies 
there  was  believed  to  be  a  direct  causal  relationship  between  the  high  air 
temperatures  and  the  increased  death  rate  of  children  in  summer,  but 
with  the  development  of  bacteriology  less  importance  came  to  be  attached 
to  the  effect  of  heat  per  se  and  much  more  to  infections  caused  by  slightly 
spoiled  foods.  When  health  departments  began  to  publish  the  results 


460  CITY  MILK  SUPPLY 

of  their  bacteriological  examinations  of  milk  the  coincidence  between  the 
high  bacterial  counts  of  summer  and  the  high  total  infant  mortality  of 
that  season  was  noted  and  further  analysis  showed  that  the  high  death 
rate  of  infants  from  intestinal  disease  and  these  high  counts  also  corre- 
sponded. So,  it  was  concluded  that  dirty  milk  was  one  of  the  causes  of 
this  sort  of  trouble  in  babies. 

Tp  determine  the  injurious  effect  of  bacteria  in  milk  on  infants  more 
exactly  and  if  possible  to  discover  what  bacteria  were  the  harmful  ones, 
Park  and  Holt  from  1901  to  1904  made  an  extensive  study  of  the  problem 
in  certain  hospitals  and  tenement  districts  of  New  York  City.  Their 
conclusions  in  part  are : 

"1.  During  cool  weather  neither  the  mortality  nor  the  health  of  the  infants 
observed  in  the  investigation  was  appreciably  affected  by  the  quality  of  the  mar- 
ket milk  or  by  the  number  of  bacteria  which  it  contained. 

"2.  During  hot  weather,  when  the  resistance  of  the  children  was  lowered, 
the  kind  of  milk  taken  influenced  both  the  amount  of  illness  and  the  mortality ; 
those  who  took  condensed  milk  and  cheap  store  milk  did  the  worst,  and  those 
who  received  breast  milk,  pure  bottled  milk  and  modified  milk  did  the  best.  The 
effect  of  bacterial  contamination  was  very  marked  when  the  milk  was  taken 
without  previous  heating;  but,  unless  the  contamination  was  very  excessive, 
only  slight  when  heating  was  employed  shortly  before  feeding. 

"3.  The  number  of  bacteria  which  may  accumulate  before  milk  becomes 
noticeably  harmful  to  the  average  infant  in  summer  differs  with  the  nature  of 
the  bacteria  present,  the  age  of  the  milk,  and  the  temperature  at  which  it  has 
been  kept.  When  milk  is  taken  raw,  the  fewer  the  bacteria  present  the  better 
are  the  results.  Of  the  usual  varieties,  over  1,000,000  bacteria  per  cubic  centi- 
meter are  certainly  deleterious  to  the  average  infant.  However,  many  infants 
take  such  milk  without  apparently  harmful  results.  Heat  of  145°F.  for  30  min. 
or  of  170°F.  for  a  shorter  period  not  only  destroys  most  of  the  bacteria  present,  but 
apparently  some  of  their  poisonous  products.  No  harm  from  the  bacteria  pre- 
viously existing  in  recently  heated  milk  was  noticed  in  these  observations  unless 
they  had  amounted  to  many  millions,  but  in  such  numbers  they  were  decidedly 
deleterious. 

"4.  When  milk  of  average  quality  was  fed,  sterilized  and  raw,  those  infants 
who  had  received  milk  previously  heated  did,  on  the  average,  much  better  in 
warm  weather  than  those  who  received  it  raw.  The  difference  was  so  quickly 
manifest  and  so  marked  that  there  could  be  no  mistaking  of  the  results. 

"5.  No  special  varieties  of  bacteria  were  found  in  unheated  milk  which 
seemed  to  have  any  special  importance  in  relation  to  the  summer  diarrheas  of 
children.  A  few  cases  of  acute  indigestion  were  seen  immediately  following  the 
use  of  pasteurized  milk  more  than  36  hr.  old.  Samples  of  such  milk  were  found 
to  contain  more  than  1,000,000  bacteria  per  cubic  centimeter,  mostly  spore- 
bearing  varieties.  The  deleterious  effects,  though  striking,  were  neither  serious 
nor  lasting. 

"6.  After  the  first  12  months  of  life  infants  are  less  and  less  affected  by  the 
bacteria  in  milk  derived  from  healthy  cattle  and  the  air.  According  to  these 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  461 

observations,  when  milk  had  been  kept  cool,  the  bacteria  did  not  appear  to  injure 
the  children  over  3  years  of  age  at  any  season  of  the  year,  unless  in  very  great 
excess. 

"7.  While  it  is  true  that  even  in  tenements  the  results  with  the  best  bottle 
feeding  are  nearly  as  good  as  average  breast  feeding,  it  is  also  true  that  most  of 
the  bottle  feeding  is  at  present  very  badly  done;  so  that,  as  a  rule,  the  immense 
superiority  of  breast  feeding  obtains." 

As  a  whole  these  extensive  studies  showed  a  less  definite  relationship 
between  dirty  milk  and  infant  mortality  than  previously  had  been  be- 
lieved to  exist  and  they  encouraged  many  other  investigations  of  this 
question  in  this  country,  a  few  of  which  may  be  noted. 

It  has  long  been  claimed  that  the  infant  mortality  was  lower  among 
breast-fed  than  among  bottle-fed  babies.  The  statement  has  been  made 
that  80  to  85  per  cent,  of  all  infant  deaths  occur  among  bottle-fed  babies 
but  even  if  this  is  true  it  does  not  necessarily  indicate  that  the  percentage 
of  deaths  among  bottle-fed  infants  is  excessive  for  if  it  should  be  true 
also,  that  80  per  cent,  of  all  infants  are  bottle-fed,  this  percentage  of 
infants'  deaths  is  what  would  be  expected  and  so  is  not  an  arraignment  of 
bottle  feeding.  Davis  has  reported  the  results  of  a  study  by  the  Boston 
City  Board  of  Health  to  determine  the  percentage  of  babies  that  are 
bottle-fed  and  has  made  some  deductions  therefrom  as  to  the  influence 
of  bottle  feeding  on  infant  mortality.  The  work  is  based  on  the  replies 
to  a  circular  letter  of  inquiry  and  on  supplementary  information  obtained 
by  board  of  health  nurses.  In  all  there  were  736  replies.  Table  118 
shows  the  nativity  of  the  mother  and  the  number  of  living  babies  at 
various  age  periods  from  2  weeks  to  1  year  old  that  were  breast-  or  bottle- 
fed  and  it  also  shows,  by  the  addition  of  the  deaths  occurring  within  the 
year  at  the  several  age  periods,  the  total  number  of  breast-  and  bottle-fed 
babies  and  the  percentages,  corrected  by  these  deaths,  for  the  various 
age  periods.  Table  119  shows  the  mortality  of  infants  in  the  City  of 
Boston  in  1911,  by  age,  nativity  of  mother  and  by  feeding.  Table  120 
shows  the  mortality  of  infants  in  the  City  of  Boston  in  1911,  by  month, 
age  and  feeding.  In  this  table  the  slight  increase  of  deaths  among  breast- 
fed babies  during  the  summer  months  is  strikingly  contrasted  with  the 
multifold  increase  in  deaths  among  bottle-fed  babies  in  July,  August 
and  September.  Table  121  is  a  comparison  of  the  actual  infant  death 
rates  and  estimated  infant  death  rates,  had  all  babies  been  breast-fed. 

"The  conclusions  that  may  be  reached  from  the  figures  in  this  last  table  are 
startling.  For  instance,  had  all  the  infants  above  2  weeks  of  age  been  breast-fed 
or  equally  well-fed,  for  there  is  reason  to  believe  that  bottle  feeding  may  be  so 
safeguarded  that  it  will  be  productive  of  no  greater  infant  mortality  than  breast 
feeding,  there  would  have  been  but  1,253  infant  deaths,  whereas  had  all  been 
bottle-fed  there  would  have  been  4,352  deaths.  The  actual  number  of  infant 
deaths  in  1911  was  2,245,  giving  an  infant  death  rate  of  127  per  1,000  births  but 


462 


CITY  MILK  SUPPLY 


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CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


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464 


CITY  MILK  SUPPLY 


had  all  the  babies  been  breast-fed  nearly  1,000  babies  would  have  been  saved 
and  the  death  rate  instead  of  being  127  would  have  been  71,  which  is  comparable 
to  the  rate  of  62  in  New  Zealand  and  to  the  rate  of  61  in  South  Australia  in  1909." 

TABLE  121. — ACTUAL  DEATH  RATES  AND  ESTIMATED  DEATH  RATES  IP  ALL  CHILDREN 
HAD  BEEN  BREAST-FED,  BOSTON,  MASS.  (DAVIS) 


Nativity  of  mother 

United 
States 

Ire- 
land 

Can- 
ada 

Italy 

Russia 
and 
Poland 

Totals 
for 
Boston 

Births   1910 

6,226 
927 

149 
59 
653 
16 
457 
470 
73 
76 

2,816 

345 
123 
73 
227 
21 
184 
161 
65 
58 

1,747 

232 
133 
51 
160 
20 
135 
97 
•77 
56 

2,703 
292 

1  08 
83 
236 
53 
205 
87 
76 
32 

2,479 
230 

93 
79 
162 

37 
145 

85 
58 
35 

17,668 
2,245 

127 
68 
1,603 
26 
1,253 
992 
71 
56 

Deaths  under  1  year,  1911  

Rate   per   1,000  births    (using  the   1910 
births)  

Percentage  of  children  between  2  weeks 
and  1  year  breast-fed  (estimated). 

Deaths,  1911,  of  children  between  2  weeks 
and  1  year      

Percentage  of  deaths  between  2  weeks  and 
1  year  breast-fed 

Estimated  total  infant  deaths,  1911,  if  all 
above  2  weeks  had  been  breast-fed 

Lives  saved  if  all  above  age  of  2  weeks  had 
been  breast-fed  

Estimated  death  rate  if  all  above  2  weeks 
had  been  breast-fed  

Estimated  reduction  in  death  rate  if  all 
above  2  weeks  had  been  breast-fed  

The  necessity  of  carefully  analyzing  infant  mortality  statistics  before 
drawing  conclusions  from  them  is  well  illustrated  by  Dr.  Williams' 
study  of  the  relation  between  infant  mortality  and  market  milk  in  the 
City  of  Rochester,  N.  Y.  His  investigation  involved:  (1)  A  critical 
examination  of  the  infant  mortality  data  of  the  city  for  the  1 1  years  from 
1900  to  1910.  (2)  A  personal  investigation  of  all  of  the  deaths  of  children 
under  5  years  of  age  who  were  reported  to  have  died  of  a  disease  of  the 
gastro-intestinal  tract  between  Aug.  1,  1910,  and  Aug.  1,  1911.  (3) 
The  visiting  of  100  to  600  homes  in  each  of  15  sections  of  the  city  and  the 
securing  in  them  of  (a)  information  as  to  the  number  of  children  under  1 
year  of  age  and  the  kind  of  food  and  method  of  feeding  employed;  (6) 
the  use  of  market,  certified  and  condensed  milks  and  of  ice. 

In  the  study  of  the  mortality  statistics,  the  ailments  of  which  children 
died  were  put  into  four  groups,  viz.:  Group  1,  diseases  of  the  digestive 
tract  and  of  nutrition;  to  these  milk  bears  a  direct  causal  relation. 
Group  2,  infectious  diseases;  .these  are  often  milk-borne.  Group  3, 
diseases  such  as  meningitis,  bronchitis  and  pneumonia  which  are  not 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


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466  CITY  MILK  SUPPLY 

milk-borne.     Group  4,  deaths  due  to  accident,  congenital  disease,  and 
other  causes  bearing  no  relation  to  food. 

It  was  found  that  a  large  number  of  children  died  of  diseases  of  the 
fourth  group  and  that  many  more  children  die  of  diseases  of  the  third 
group  which  are  not  attributable  to  milk,  than  of  diseases  of  the  second 
group  which  are  sometimes  milk-borne.  The  number  of  deaths  that 
occur  in  group  2  does  not  convey  a  correct  idea  of  its  importance,  for 
many  children  contract  non-fatal  bovine  tuberculosis  from  milk.  The 
deaths  in  group  1  are  caused  by  diseases  to  which  milk  has  a  direct  rela- 
tion. So  it  is  commonly  used  in  studying  the  relation  of  market  milk  to 
infant  mortality  because  diseases  of  the  three  other  groups  are  more 
remotely  or  not  at  all  related  to  it.  In  such  studies  only  the  deaths  of 
children  under  1  year  of  age  should  be  used  because  so  many  complicat- 
ing factors  enter  into  the  lives  of  older  children  that  the  relation  of  milk 
to  illness  becomes  less  definite. 

As  the  result  of  plotting  the  yearly  death  rate  per  1,000  of  population 
in  children  under  1  year  of  age  and  the  average  yearly  bacterial  count  of 
the  milk  for  each  year  of  the  period  from  1910  to  1911,  Dr.  Williams 
showed  there  was  no  correspondence  between  the  two.  A  comparison 
between  the  yearly  infant  mortality  rates  and  these  bacterial  counts 
would  have  been  more  illuminating. 

Because  death  certificates  often  do  not  give  data  beyond  the  imme- 
diate cause  of  death  and  because  they  are  often  made  out  by  coroners 
and  physicians  that  have  no  intimate  knowledge  of  the  case,  they  are 
often  misleading.  So  all  the  deaths  of  children  under  5  years  of  age 
which  occurred  in  the  period  from  Aug.  1, 1910,  to  Aug.  1, 1911,  and  which 
the  death  certificates  attributed  to  diseases  of  the  first  groups  were 
studied  in  detail.  The  results  of  these  studies  appear  in  Table  122. 

It  was  found  that: 

~^f, 

"1.  Many  of  the  poor  families  moved  within  a  year,  showing  that  they  led 
a  hand-to-mouth  existence. 

"2.  That  many  of  these  poor  parents  went  to  work,  leaving  the  children  with 
neighbors  or  to  fend  for  themselves. 

"3.  That  many  poor  children  lacked  proper  medical  attention  and  that  many 
of  them  were  doctored  by  the  mother  or  at  the  nearest  drug  store.  A  large  num- 
ber of  children  die  unattended  by  a  physician.  The  certificates  are  made  out 
by  the  coroner  and  in  the  table  are  listed  under  the  heading  '  No  Records  Obtain- 
able.* There  is  good  reason  to  believe  that  they  properly  belong  with  the  cases 
that  died  from  bad  care  and  neglect. 

"4.  Seventy-five  children  died  of  bad  care  and  neglect  and  in  87  cases  there 
was  a  definite  history  of  improper  feeding  which  often  meant  too  frequent  feeding 
of  improperly  prepared  food  or  of  the  breast  milk. 

"5.  Of  156  children  that  died  under  1  year  of  age,  30  were  exclusively  breast- 
fed, 27  were  breast-fed  and  received  other  food  besides.  28  received  cow's  milk 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  467 

exclusively  and  56  were  fed  proprietary  foods  which  in  17  instances  means  con- 
densed milk.  The  large  number  of  deaths  among  breast-fed  children  suggests 
other  factors  than  feeding  as  the  cause  of  death. 

"6.  Many  children  who  die  of  bowel  diseases  are  inherently  poorly  born; 
13  of  these  children  were  premature  and  41  gave  a  possible  history  of  congenital 
disease.  Of  the  latter  the  parents  of  14  have  clear  visual  symptoms  of  tubercu- 
losis or  of  gonorrhea. 

"7.  A  study  of  milk  consumption  in  5,731  homes  with  526  babies  led  to  the 
conclusion  that  at  least  60  per  cent,  of  the  babies  are  breast-fed,  that  15  per  cent, 
are  fed  on  cow's  milk  and  that  10  per  cent,  are  fed  on  proprietary  foods. 

"  The  total  milk  consumption  of  the  city  was  90,000  qt.  Of  this  amount  about 
3,250  qt.  are  retailed  daily  in  stores,  1,950  qt.  being  dispensed  in  bottles  and  1,300 
qt.  as  dipped  milk.  The  latter  is  very  dirty  food  and  a  menace  to  the  customers. 
The  store  milk  is  sold  where  the  poor  live  and  where  infant  mortality  is  highest. 
The  city  consumes  about  5,500  cans  of  condensed  milk  daily. 

"8.  While  the  study  shows  that  about  six  times  as  many  babies  are  nursed 
as  are  fed  on  cow's  milk  and  proprietary  foods  yet  more  than  twice  as  many  babies 
of  the  latter  class  die  as  of  the  former. 

"9.  The  more  important  factors  in  the  group  of  causes  of  the  infant  mortality 
were: 

(A]  Diseased  or  physically  unfit  parents. 

(J5)  Dirty,  disease-breeding  homes. 

(C)  Neglect  and  bad  care. 

(D)  Improper  methods  of  feeding  and  the  use  of  ill-suited  foods. 

(E)  Dirty  and  disease-carrying  milk." 

Dr.  Price,  the  health  officer  of  Detroit,  Mich.,  has  recently  told  how 
the  infant  mortality  in  that  city  was  greatly  reduced  by  attention  to 
factors  quite  independent  of  the  milk  supply.  The  first  move  was  to 
get  the  births  as  completely  reported  as  possible,  for  the  effect  of  this 
may  be  to  considerably  reduce  the  infant  mortality  rate.  A  city  with 
an  infant  mortality  of  200  per  1,000  births  with  only  half  the  births  re- 
ported would  have  a  death  rate  of  100  per  1,000  births  if  all  of  the  births 
were  recorded.  The  next  step  was  to  proceed  to  actually  reduce  the 
number  of  deaths  of  infants. 

The  city  was  divided  into  498  districts  of  six  to  eight  blocks  each  and 
the  births  and  deaths  of  babies  in  each  district  was  tabulated.  Then 
births  were  spotted  in  red  and  the  deaths  in  black  on  a  map  of  the  district. 
This  work  showed  that  each  district  might  be  placed  in  one  of  the 
following  groups : 

1.  No  deaths. 

2.  Deaths  1    to  10  per  cent,  of  the  births. 

3.  Deaths  10  to  20  per  cent,  of  the  births. 

4.  Deaths  20  to  40  per  cent,  of  the  births. 

5.  Deaths  more  than  40  per  cent,  of  the  births. 

On  July  1,  1914,  that  is,  at  the  beginning  of  the  most  trying  season 
for  babies  and  in  what  proved  to  be  a  hard  summer  for  babies,  four  of  the 


468 


CITY  MILK  SUPPLY 


board  of  health  nurses  were  put  into  the  districts  where  infant  mortality 
was  greater  than  20  per  cent.  Each  nurse  was  instructed  to  reduce 
infant  mortality  by  reducing  infant  morbidity  and  her  reliance  was  to  be 
her  own  ability  to  instruct  in  and  demonstrate  the  hygienic  care  and 
feeding  of  babies.  Each  nurse  was  furnished  with  a  map  of  her  district 
showing  by  a  red  dot  where  there  was  a  baby  under  a  year  old  and  by  a 
black  one  where  the  death  of  a  baby  had  occurred.  The  maps  showed  the 
location  of  each  street,  alley,  house,  barn  and  privy.  The  nurses  worked 
from  house  to  house  and  each  nurse  had  100  to  150  babies  to  care  for. 
No  milk  stations  or  other  baby-saving  agencies  were  in  the  immediate 
neighborhood  of  any  of  these  districts  nor  were  any  established.  The 
results  attained  are  illustrated  by  those  in  the  four  districts  given  in 
Table  123. 

TABLE  123. — REDUCTION  OF  INFANT  MORTALITY  IN  DETROIT,  MICH.,  IN  1914,  BY 

DISTRICT  NURSES  (PRICE) 


Period 

District 

Births 

Deaths 

Ratio, 
3  months 

Ratio, 
6  months 

Ratio, 
9  months 

Jan.—  Mar 

5-340 

36 

9 

0  250 

Apr  —June 

26 

4 

0  153 

0  210 

July-Sept. 

20 

3 

0.150 

0.195 

Jan  —Mar 

11-440 

19 

3 

0  157 

Apr  —June 

18 

5 

0  276 

0  216 

July-Sept. 

26 

2 

0.077 

0.158 

Jan  —Mar 

16-320 

56 

10 

0  178 

Apr.—  June  

62 

8 

0.129 

0.152 

July-Sept. 

63 

6 

0.095 

0.132 

Jan.—  Mar 

16-400 

29 

6 

0  206 

Apr  —June 

16 

8 

0  500 

0  310 

July-Sent. 

38 

2 

0  050 

0.195 

Summary  of  the  Four  Districts,  5-340,  11-440,  16-320  and  16-400 


Jan.—  Mar  

140 

28 

0.200 

Apr.—  June  .  .  . 

122 

25 

0  205 

0.202 

July-Sent. 

147 

13 

0  088 

0.161 

Jan.—  Mar  

Rest  c 
4,527 

)f  city 
615 

0.136 

Apr.—  June 

4,526 

468 

0  103 

0.119 

July-Sept 

4850 

649 

0  134 

0.125 

These  excellent  results  were  brought  about  by  correcting  errors  that 
are  so  wrong  that  many  will  wonder  that  the  mistakes  could  have  been 
made  of  committing  them;  they  include  such  things  as  these: 

1.  Feeding  babies  beer,  coffee,  sausage,  etc. 

2.  Allowing  the  dirty  uncovered  nursing  bottle  to  stand  on  the  kitchen 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  469 

table  and  pouring  cold  milk  into  it  to  feed  right  to  the  baby.     No  attempt 
at  modifying  milk. 

3.  Mother  taking  no  care  of  her  hands;  as,  for  instance,  preparing 
the  babies'  food  without  washing  them  after  handling  the  diapers. 

4.  Keeping  the  baby  bundled  up  near  the  stove  or  in  some  other 
unsuitable  place. 

5.  Bathing  the  baby  improperly. 

This  reduction  of  the  infant  mortality  rate  was  accomplished  without 
in  any  case  changing  the  milk  supply  of  the  neighborhood  except  that 
an  earnest  effort  was  made  to  eliminate  the  use  of  condensed  milk.  De- 
troit has  a  good  milk  supply  and  Dr.  Price  says  distinctly  that  these 
results  would  not  have  been  possible  had  it  been  otherwise  but  the  point 
is  that  an  excessive  infant  mortality  is  not  wholly  attributable  to  the 
milk  and  that  the  best  of  milk  cannot  make  up  for  the  errors  of  bad 
mothering. 

Flies  are  generally  believed  to  be  a  factor  in  infant  mortality  but  it 
is  difficult  to  determine  how  large  a  part  they  play.  It  certainly  must 
vary  a  great  deal.  They  are  probably  more  important  in  the  warm 
Southern  cities  than  in  the  cool  Northern  ones  and  in  a  city  or  ward 
without  sewerage  and  without  garbage  collection  than  in  places  that 
have  these  facilities.  They  are  also  more  menacing  in  a  dirty  house 
than  in  a  clean  one.  Several  studies  have  been  made  to  ascertain  the 
importance  of  fly  infection  but  owing  to  the  many  complicating  factors 
involved  final  conclusions  have  been  drawn  in  few  cases.  Recently 
Platt  of  the  New  York  Association  for  Improving  the  Condition  of  the 
Poor  has  outlined  the  chief  results  of  an  extensive  cooperative  investiga- 
tion by  the  Association  of  the  question  of  the  relation  of  the  fly  to  infan- 
tile diarrhea.  The  findings,  expressed  in  certain  factors  devised  by  the 
investigators,  are  that  the  fly  has  an  importance  in  causing  this  rate  of 
1.9,  "dirt"  1.8,  artificial  feeding  2.4,  flies  and  "dirt"  2.4  and  artificial 
feeding  and  "dirt"  3.5.  By  "dirt"  is  meant  the  conditions  found  in 
homes  presided  over  by  easy-going  mothers  who  are  satisfied  with  mini- 
mum standards  of  decency  with  the  result  that  everything  is  at  loose 
ends  and  the  house  is  littered  with  remnants  of  meals,  dirty  clothes,  etc. 
In  discussing  this  paper  Dr.  Levy  emphasized  the  importance  of 
proper  excrement  disposal  in  Southern  cities  and  the  part  played  by 
flies  in  distributing  feces.  He  stated  that  since  1911,  the  board  of  health 
nurses  of  Richmond,  Va.,  had  been  instructed  to  emphasize  to  mothers 
the  importance  of  properly  caring  for  soiled  diapers.  The  effect  of  laying 
stress  on  this  point  was  gratifying.  The  city  had  an  excellent  milk 
supply  for  6  years  and  general  instructions  in  the  care  of  babies  had  been 
given  for  2  years;  still,  the  infant  death  rate  from  diarrhea  per  100,000 
inhabitants  ranged  from  122  to  152  but  when  the  nurses  added  to_ their 
other  instruction,  information  on  the  care  of  babies'  excrement  this  death 


470  CITY  MILK  SUPPLY 

rate  fell  to  101  in  1912  and  to  84  in  1913  with  indications  that  it  would 
drop  to  between  70  and  75  in  1914.  Flies,  of  course,  are  one  means  of 
spreading  the  stools  of  babies  about. 

No  one  who  has  done  tenement  house  inspection  and  seen  the  overfull 
privies  in  the  back  yards  and  the  unscreened  windows  and  has  observed 
milk  with  a  lot  of  struggling  drowning  flies  in  it  standing  in  the  hot 
kitchens  and  has  watched  the  flies  swarming  over  the  nursing  bottles 
has  a  particle  of  doubt  but  that  in  such  habitations  food,  flies  and  feces 
get  badly  mixed. 

Other  phases  of  the  problem  of  infant  mortality  have  been  brought 
out  by  Schereschewsky  in  his  paper  on  "Heat  and  Infant  Mortality." 
In  showing  the  relation  of  temperature  to  infant  deaths  it  has  been  cus- 
tomary to  compare  the  mean  temperatures  for  weekly  or  monthly  periods 
with  the  infant  deaths  in  like  periods  but  Liefman  and  Lindeman  in  a 
study  of  the  infant  mortality  of  Berlin,  Germany,  and  also  others  have 
shown  that  to  study  the  direct  effect  of  heat  upon  infant  mortality  the 
daily  temperatures  and  daily  deaths  must  be  compared.  By  using  curves 
constructed  on  this  basis  these  two  authors  have  demonstrated  a  well- 
marked  parallelism  in  the  temperature  and  mortality  curves  and  have 
noted  two  well-marked  peaks  in  the  mortality  curve.  These  indicate 
excessive  mortality  in  early  summer  and  in  late  summer. 

The  early  summer  mortality  appears  with  the  first  atmospheric 
temperatures  above  73.4°  and  recedes  shortly  with  the  advent  of  cooler 
weather.  In  cool  years  this  early  summer  mortality  may  be  lacking. 
In  this  mortality  many  deaths  occur  after  an  illness  of  1  to  2  days  and  the 
deaths  occur  from  causes  mainly  referable  to  affections  of  the  central 
nervous  system. 

The  late  summer  mortality  extends  from  the  middle  or  end  of  July 
to  the  first  of  September,  but  in  cool  summers  may  be  absent.  It  does 
not  recede  with  the  first  cool  weather  but  is  well-sustained  and  does  not 
drop  markedly  till  the  close  of  the  year.  It  seems  to  express  the  sum- 
mation of  the  effects  of  a  long  heated  period  plus  irregularities  caused  by 
sudden  increases  in  temperature.  As  summer  progresses  the  number 
of  deaths  from  gastro-intestinal  diseases  increases  till  by  the  end  of 
August  70  per  cent,  of  the  death  certificates  give  diseases  of  this  class 
as  the  cause  of  death.  Hot  days  increase  the  number  of  acute  cases 
but  these  dwindle  in  late  summer.  The  fact  that  the  late  summer  mor- 
tality curve  does  not  drop  with  the  advent  of  cooler  weather  would  seem 
to  suggest  other  causes  of  illness  than  high  temperature  but  such  is  not 
the  fact.  It  is  because  the  temperatures  indoors  do  not  drop  with  the 
outside  air  temperatures  that  the  death  curve  is  maintained. 

Observations  both  in  Europe  and  this  country  show  that  the  indoor 
temperature  is  often  higher  than  outside  temperatures.  The  slow  diffu- 
sion of  heat  through  the  walls  is  in  large  measure  responsible  for  this. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  471 

Houses  with  good  air  circulation  cool  off  more  quickly  than  those  that 
lack  it.  The  number  of  infant  deaths  is  greatest  in  houses  and  districts 
of  the  city  having  poor  air  circulation.  It  has  been  observed  that  the 
infant  mortality  is  less  for  children  living  in  cellars  and  basements  than 
for  breast-fed  children  living  in  warmer  rooms.  The  mortality  is  greatest 
under  the  roof  where  it  is  hottest. 

The  observations  in  regard  to  the  effect  of  humidity  are  meager  and 
contrary  to  what  would  be  expected,  for  they  indicate  that  infant  mor- 
tality is  highest  on  hot  dry  days.  In  overcrowded  tenements  the 
humidity  is  excessive  owing  to  emanations  from  the  lungs  and  skin. 

Heat  produces  many  effects  on  the  child.  It  increases  metabolism 
and  favors  heat  retention.  The  regulation  of  heat  by  the  body  is  efficient 
within  narrower  limits  in  babies  than  adults  so  that  high  temperatures 
are  apt  to  raise  the  body  temperature  of  children  above  normal.  In 
hot  weather  babies  and  adults  both  have  reduced  tolerance  for  food. 
This  in  part  accounts  for  the  better  results  obtained  by  breast  feeding 
in  hot  spells  than  by  bottle  feeding.  The  baby  takes  the  first  mother's 
milk  and  is  satisfied,  leaving  the  rich  after  milk  behind  whereas  in  bottle 
feeding  the  composition  of  the  milk  is  fixed  and  if  the  baby  eats  at  all, 
it  is  likely  to  overeat.  In  hot  weather  the  quantity,  acidity  and  activity 
of  the  gastric  juice  is  reduced.  Certain  experiments  on  laboratory 
animals  lead  to  the  belief  that  the  resistance  to  bacteria  is  reduced  by 
heat. 

Typical  cholera  infantum  is  believed  by  many  to  be  a  direct  heat 
effect  and  heat  is  supposed  to  have  a  predisposing  effect  toward  subacute 
diarrheas  because  it  induces  reduced  tolerance  of  food,  reduced  activity 
of  the  digestive  secretions  and  reduced  normal  resistance  of  the  intestines 
to  bacterial  invasion.  Besides  these  diarrheas  there  are  the  infectious 
diarrheas  due  to  specific  organisms.  Flexner,  Kendall  and  Walker  and 
others  have  proved  certain  cases  of  diarrhea  of  infants  to  be  due  to  B. 
dysenterice,  and  the  last  two  investigators  found  certain  other  cases  to 
be  caused  by  B.  welchii  infections.  Other  bacteriologists  have  attributed 
certain  outbreaks  of  diarrhea  to  other  germs. 

In  general,  infant  mortality  is  class  mortality ;  it  is  begotten  by  poverty, 
ignorance  and  crime.  The  poor  live  in  overcrowded  insanitary  condi- 
tions. The  expectant  poor  mother  has  to  work  till  she  is  confined  and 
has  to  leave  her  offspring  soon  after,  thereby  depriving  it  of  nature's 
food  and  entrusting  its  care  to  some  "  little  mother."  The  baby  suffers 
from  bad  food,  injudicious  feeding  and  other  forms  of  ignorance. 
Criminal  parents  are  apt  to  be  alcoholics,  the  sufferers  from  venereal 
disease  and  often  to  be  mentally  weak.  Illegitimacy  means  that  the 
newborn  is  likely  to  receive  gonorrhea  and  syphilis  from  its  parents  and 
to  be  neglected  by  them.  In  England  and  Wales  in  1909  the  death  rate 
of  illegitimate  children  was  211.1  and  of  legitimate  children  104. 


472  CITY  MILK  SUPPLY 

The  subject  of  infant  mortality  has  been  merely  crudely  outlined  in 
the  preceding  paragraphs  but  it  cannot  be  pursued  further.  Enough 
has  been  said  to  show  that  dirty  and  infected  milk  is  responsible  for  part 
of  it,  but  it  cannot  be  successfully  maintained  that  it  is  for  all  of  it.  Any 
health  officer  who  expects  to  reduce  the  infant  mortality  rate  to  where 
it  ought  to  be  by  the  sole  agency  of  a  clean  milk  crusade  deludes 
himself. 

One  method  of  coping  with  the  problem  of  infant  mortality  adopted 
by  boards  of  health  is  to  try  to  reach  the  mother  in  the  home.  Circulars 
are  issued  to  expectant  mothers  telling  them  to  get  medical  advice,  giving 
them  simple  rules  in  regard  to  dressing,  exercise,  eating  and  bathing  and 
warning  them  not  to  use  patent  medicines.  Some  boards  employ  nurses 
and  in  summer  have  them  devote  much  of  their  time  to  teaching  the  poor 
how  to  care  for  babies.  There  is  less  effort  to  reach  the  well-to-do  but 
they  are  sent  circulars  on  the  care  of  milk  in  the  home  which  emphasize 
the  necessity  of  being  particularly  careful  in  the  selection  and  care  of 
milk  for  babies  and  tell  how  to  pasteurize  it.  Some  of  these  circulars 
touch  on  the  use  of  bottles  of  the  thermos  type  for  holding  milk  and 
other  liquids  that  are  subject  to  bacterial  decomposition. 

Bottles  of  the  Thermos  Type. — Such  bottles  have  been  studied  from 
this  standpoint  by  Rogers,  by  Tonney  and  by  Davis.  Rogers  showed 
that  these  bottles  act  as  very  effective  incubators  when  their  contents 
reach  the  temperature  of  bacterial  multiplication  that  is  between  50° 
and  98°F.  Milk  put  in  them  at  a  temperature  of  102°F.  and  containing 
23,900  bacteria  per  cubic  centimeter  in  4J^  hr.  had  a  temperature  of 
95°F.  and  had  1,420,000  bacteria  per  cubic  centimeter  and  in  ?K  hr- 
its  temperature  dropped  to  93°F.  and  its  bacterial  count  had  increased 
to  27,000,000  bacteria  per  cubic  centimeter.  If  inadequately  cooled 
milk,  that  is  milk  at  about  the  temperature  it  would  have  in  the  ordinary 
ice  chest,  was  put  in  them  it  soon  reached  a  temperature  where  rapid 
bacterial  multiplication  took  place;  thus  milk  put  in  the  bottles  at  46.4°F. 
and  containing  49,000  bacteria  per  cubic  centimeter  in  24  hr.  had  a  tem- 
perature of  64°F.  and  a  bacterial  count  of  2,140,000  per  cubic  centimeter. 
Thoroughly  cooled  milk  kept  well.  If  put  in  the  bottle  at  23°F.  with  a 
bacterial  count  of  29,000  per  cubic  centimeter  in  24  hr.  the  temperature 
was  but  37.4°F.  and  the  count  36,000  bacteria  per  cubic  centimeter 
and  in  48  hr.  the  temperature  was  57.2°F.  and  the  count  only  124,000 
per  cubic  centimeter.  Tonney  showed  that  milk  might  be  put  in  these 
bottles  at  a  temperature  of  150°F.  and  kept  for  6  to  8  hr.  without  bacterial 
multiplication  ensuing  but  that  as  soon  as  the  temperature  of  the  milk 
drops  to  about  115°F.  rapid  bacterial  multiplication  took  place.  Davis 
showed  that  the  bottles  cannot  be  sterilized  by  washing  them  with  boiling 
hot  water  and  that  in  12  hr.,  milk  that  had  been  heated  to  various  tem- 
peratures between  120°F.  and  212°F.  had  bacterial  counts  so  high  that 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  473 

its  use  was  unsafe.  From  these  investigations  it  appears  that  the  use  of 
these  bottles  for  holding  milk  and  other  liquids  subject  to  bacterial  de- 
composition is  commendable  when  the  temperature  is  kept  below  50°F. 
but  that  they  become  highly  dangerous  if  the  temperature  is  allowed  to 
rise  above  this  point.  They  should  never  be  used  to  hold  hot  perishable 
foods. 

Child  Welfare  Stations. — Besides  these  rather  general  methods  of 
combating  infant  mortality  the  child  welfare  stations  or  infant  milk 
depots  are  used  in  more  definite  campaigns  against  the  evil.  In  France 
they  may  be  traced  back  to  the  "L'Oevre  de  la  Maternite"  founded  in 
1890  by  Hergott  at  Nancy.  The  mothers  of  children  born  in  the  institu- 
tion under  his  charge  were  required  to  bring  their  babies  back  for  examina- 
tion 1  month  after  birth  and  were  given  a  present  of  money  if  satisfactory 
progress  had  been  made.  This  charity  was  the  precursor  of  the  "  Con- 
sultation de  Nourrisson"  founded  by  Boudin  at  the  Charite"  Hospital  at 
Paris  in  1892,  at  the  Maternite  Hospital  in  1895  and  at  the  Clinique 
d'Accouchement  Tarnier  in  1898.  There  are  two  types  of  consultation 
de  nourrisson,  namely:  (1)  those  attached  to  maternity  hospitals  where 
the  mothers  are  accouched  in  the  hospital  free  of  charge  and  their  babies 
kept  under  medical  supervision  for  2  years  succeeding  birth;  and  (2) 
those  not  attached  to  maternity  hospitals.  The  two  sorts  of  institutions 
are  conducted  in  the  same  way.  Every  effort  is  made  to  encourage 
breast  feeding  but  where  it  is  impossible  for  the  mother  to  nurse  her 
baby,  sterilized  milk  is  supplied.  Weekly,  the  mother  must  bring  the 
baby  to  the  hospital  where  one  of  the  medical  staff  examines,  weighs  it 
and  records  its  weight  and  other  particulars. 

An  offshoot  from  the  Consultation  de  Nourrisson  is  the  "goutte  de 
lait"  which  is  in  reality  a  milk  dispensary  from  which  babies  are  fed  upon 
sterilized  milk  without  modification.  Breast  feeding  is  encouraged  but 
usually  the  great  majority  of  infants  are  bottle-fed.  The  first  goutte 
de  lait  was  established  by  Variot  at  Paris  in  1892  in  connection  with  the 
Belleville  dispensary.  The  name  goutte  de  lait  was  first  used  by  Leon 
Dufour  who  gave  it  to  the  institution  he  established  at  Fecamp  in  1894 
which  was  the  first  separate  institution  of  this  sort  and  the  first  provincial 
goutte  de  lait.  These  institutions  sprang  up  all  over  France  and  in  all 
countries  of  the  world  where  cow's  milk  is  used.  The  first  goutte  de  lait 
in  the  United  States  was  established  by  Hoplik  at  the  Eastern  Dispensary 
now  called  the  Good  Samaritan  in  New  York  City  in  1889.  This  was 
followed  by  the  milk  stations  of  Nathan  Straus  in  the  same  city  in  1893. 
Philanthrophists  and  charitable  organizations  of  various  sorts  established 
them  first  in  the  large  cities  and  then  in  the  smaller  ones  till  now  there 
is  nothing  unusual  about  a  milk  station.  Goler,  the  health  officer  in 
Rochester,  N.  Y.,  started  the  first  station  to  be  operated  by  a  board  of 
health.  The  innovation  attracted  much  attention  and  resulted  in  it 


474  CITY  MILK  SUPPLY 

being  recognized  that  the  maintenance  of  these  depots  may  properly 
be  one  of  the  municipal  health  department's  functions. 

With  regard  to  the  milk  stations  in  the  United  States  a  brief  state- 
ment should  be  made.  Their  object  is  to  reduce  sickness  and  death 
among  babies  which  they  do  by  charitable  practices,  furnishing  medical 
advice  and  by  educative  effort  among  the  mothers.  Since  they  aim  to 
reach  babies  most  of  their  milk  is  furnished  to  infants  under  1  year  of 
age  and  practically  all  of  it  to  children  under  3,  but  some  milk  is  supplied 
to  expectant  mothers  and  to  invalids.  Almost  all  of  the  stations  are 
under  medical  supervision  and  in  the  large  ones  well-supplied  with  money, 
the  regular  staff  consists  of  a  physician,  a  registered  nurse  and  a  matron. 
As  each  baby  is  brought  to  the  station  it  is  given  an  examination  by  the 
physician,  it  is  weighed  and  its  record  on  the  books  of  the  station  is 
started.  If  the  child  is  in  need  of  medication,  it  is  given.  The  mother  is 
encouraged  to  feed  the  child  from  the  breast  but  if  there  is  a  deficiency  of 
breast  milk,  enough  milk  is  sold  her  to  eke  out  the  needs  of  the  child  or 
if  breast  feeding  is  impossible  she  is  allowed  to  purchase  all  the  child 
needs.  The  milk  is  usually  pasteurized  but  some  stations  furnish  cer- 
tified milk  and  many  modified  milk.  The  milk  is  usually  put  up  in  bottles 
each  of  which  holds  a  single  feeding.  Some  stations  sell  milk  both  in 
these  small  bottles  and  in  ordinary  bottles.  The  mothers  are  instructed 
in  the  care  of  the  child,  of  themselves  and  in  proper  feeding  of  the  babies. 
They  are  also  taught  how  to  modify  milk.  Generally  the  great  majority 
of  the  patrons  of  the  stations  use  milk  and  so  an  ample  supply  of  good 
clean  milk  is  essential  to  the  success  of  the  station.  Milk  is  sold  at 
cost  but  even  so  it  often  happens  that  it  is  higher-priced  than  dipped 
milk  that  is  sold  in  the  neighborhood,  consequently  it  has  to  be  made 
plain  to  the  mothers  that  it  is  worth  more.  Some  cannot  pay  the  differ- 
ence in  price  and  others  are  too  poor  to  pay  at  all.  Such  people  must  be 
helped  and  this  is  done  either  from  the  funds  of  the  station  or  through 
the  agency  of  established  charities.  Ice  is  necessary  to  keep  milk  in  the 
homes  but  often  there  is  none  so  that  the  station  has  to  see  that  ice  is 
provided  and  it  often  happens  that  a  considerable  ice  charity  develops. 
Usually  regular  attendance  is  made  a  condition  of  obtaining  milk. 

The  location  of  the  stations  is  important;  they  ought  to  be  placed 
where  there  are  many  babies  in  need  of  help.  In  this  matter  the  advice 
of  the  health  department  is  to  be  sought.  The  sphere  that  a  station  can 
occupy  is  limited.  About  300  babies  is  the  maximum  number  it  can 
serve  well  and  a  nurse  should  not  be  expected  to  look  out  for  more  than 
100  babies  or  at  most  150.  The  building  occupied  should  be  convenient 
of  access  but  its  rent  need  not  be  high.  If  possible  there  should  be  three 
rooms,  a  large  one  for  dispensing  the  milk  and  for  lectures,  a  room  for 
preparing  the  milk  and  a  consultation  room  for  the  doctor  and  nurses. 

In  opening  a  new  station  the  patronage  must  be  built  up.     Conspicu- 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  475 

ous  notices  of  the  station  placed  in  the  shops,  drug  stores  and  saloons  of 
the  neighborhood  help.  Newspaper  publicity  is  of  great  value  but  the 
house  to  house  canvassing  of  the  nurses  is  most  important.  One  criti- 
cism that  is  made  of  milk  stations  is  that  they  fail  to  reach  those  who 
need  help  most.  The  overburdened  discouraged  tenement  house  mother 
does  not  find  the  time  and  energy  to  go  out  for  the  relief  that  is  at  hand;  it 
must  be  brought  to  her.  The  nurse  must  not  only  interest  the  mother  in 
the  station  and  make  her  its  patron  but  must  win  her  confidence  enough 
to  be  allowed  to  straighten  out  the  home  and  to  advise  in  the  feeding 
of  other  children.  If  extreme  poverty  exists,  its  cause  must  be  found  and 
the  effort  made  to  alleviate  it.  Once  the  mother  is  made  a  patron  of 
the  station  she  can  usually  be  made  to  feel  that  she  is  doing  well  to  spread 
its  virtues  among  her  neighbors  and  bring  them  to  it,  too.  The  6th 
Annual  Report  of  the  Boston  Milk  and  Baby  Hygiene  Association  ^tates 
that  40  per  cent,  of  the  babies  came  to  the  stations  from  mothers  and 
friends,  18.5  per  cent,  from  board  of  health  nurses,  10  per  cent,  from 
district  nurses,  13  per  cent,  from  milk  station  nurses,  13.5  per  cent, 
from  doctors  and  hospitals,  2.5  per  cent,  from  settlements,  1  per  cent, 
from  relief  agencies  and  1.5  per  cent,  from  miscellaneous  sources.  Of 
course,  elsewhere  it  would  very  likely  be  different  but  this  statement  is 
interesting  as  showing  the  influence  of  mothers  and  nurses  in  upbuilding 
station  work. 

The  proportion  of  sick  and  well  babies  treated  at  different  milk 
stations  varies  a  great  deal  and  so  does  the  infant  mortality  at  the  differ- 
ent stations.  The  efficiency  of  station  management,  the  character  of  the 
population  served,  whether  or  not  it  stands  in  great  need  of  the  help  the 
station  offers,  and  the  activity  of  the  nurses  in  ferreting  out  ailing  children, 
all  are  factors  in  determining  the  record  of  the  station  in  these  matters. 

The  educational  work  carried  on  by  the  stations  is  of  the  utmost 
importance.  The  distribution  of  leaflets  in  various  languages  telling 
about  the  station,  how  to  care  for  the  baby  and  how  to  feed  it  are  helpful 
but  the  great  work  of  this  sort  is  the  lecture  and  demonstration  work  at 
the  station.  In  carrying  on  this,  effort  should  be  made  to  reach  the  "  little 
mothers"  both  because  it  teaches  them  how  to  care  for  their  charges  and 
because  it  prepares  them  for  motherhood.  Some  stations  distribute 
small  prizes  to  the  children  for  essays  on  topics  developed  in  the  lectures. 
The  compositions  are  often  naively  touching  and  show  the  vital  interest 
taken. 

Milk  stations  by  extending  their  work  frequently  become  true  child 
welfare  stations.  They  can  do  prenatal  work  among  the  mothers,  exer- 
cise control  over  the  midwives  by  making  them  feel  that  their  work  is 
under  observation,  follow  up  foster  mothers  in  charge  of  boarded  babies 
and  teach  mothers  how  to  feed  and  bring  up  children  under  school  age. 
This  last  work  is  very  important  for  ordinarily  these  children  escape  all 


476  CITY  MILK  SUPPLY 

care  except  such  as  their  busy  mothers  and  the  streets  give  them.  They 
have  precious  little  medical  attention  and  often  suffer  for  the  need  of  such 
advice  as  the  school  physician  might  give. 

To  be  successful  a  station  must  have  good  financial  management. 
Station  expenses  fall  under  the  heads  of  (1)  supervision,  (2)  maintainance, 
(3)  medical  and  (4)  loss  on  sales,  including  relief  granted.  A  competent 
treasurer  should  handle  the  receipts  and  disbursements  and  should 
render  an  audited  account  every  year. 

In  the  large  cities  other  organizations  carry  on  relief  work  for  sick 
babies  that  helps  to  reduce  the  infant  death  rate.  For  instance,  in 
Boston  in  summer  the  floating  hospital  carries  on  a  valuable  work  in 
taking  these  babies  down  the  harbor  out  of  the  heat  of  the  city  and  in 
giving  them  medical  treatment.  Its  scientific  staff  make  bacteriological 
investigations,  studies  on  milk,  on  feeding,  etc. 

Milk  Supplies  of  Large  and  Small  Cities  Contrasted. — Since  the  milk 
supplied  small  cities  is  produced  in  the  surrounding  country  and  is  dis- 
tributed when  only  a  few  hours  old  and  since  the  farmers  would  naturally 
be  presumed  to  take  a  keen  interest  in  the  business,  inasmuch  as  they 
deliver  their  own  milk  to  customers  with  whom  they  are  acquainted, 
those  who  are  unfamiliar  with  such  supplies  might  think  them  to  be 
better  than  those  of  the  big  cities  but  often  such  is  not  the  case.  Usually 
there  is  only  a  small  amount  of  capital  invested  in  the  milk  business  of 
small  cities,  consequently  the  animals  are  poorly  housed  and  the  dairies 
meagerly  equipped.  Theoretically,  the  dairy  business  in  the  small 
places  is  protected  by  laws  but  practically  it  is  not  for  there  are  neither 
funds  nor  officials  to  enforce  them.  There  are  no  inspectors  and  no 
laboratory  facilities,  therefore  there  is  no  one  to  instruct  the  dairymen 
in  the  modern  methods  of  milk  production  nor  to  uphold  the  legal  re- 
quirements for  market  milk.  The  citizens  commonly  give  little  thought 
to  the  milk  supply,  know  very  little  about  milk  and,  failing  to  appreciate 
the  importance  of  a  good  milk  supply,  are  unresponsive  to  efforts  to  im- 
prove it.  The  small  tradesman,  being  apprehensive  that  public  discus- 
sion of  the  milk  question  and  inspection  of  dairies  will  offend  the  farmers 
and  result  in  the  withdrawal  of  their  trade,  discourage  movements  to 
better  the  milk  supply.  The  consequence  of  all  this  is  that  there  is 
virtually  no  standard  of  milk  quality,  that  slovenly  competition  creeps 
in,  that  milk  is  sold  cheap,  and  that  more  or  less  adulteration  of  the  milk 
is  practised.  In  not  a  few  towns  the  milk  business  does  not  pay  and  there 
is  dearth  of  milk.  Sometimes  these  small  places  suffer  from  milk-borne 
infections  without  knowing  it.  Bolduan  traced  the  undue  prevalence 
of  typhoid  fever  for  the  past  25  or  30  years  in  Camden,  N.  J.,  to  one  of 
the  local  milk  dealers  who  was  a  carrier.  Hill  found  that  all  typhoid 
fever  in  North  Branch,  Minn.,  for  5  years  was  derived  from  the  wife  of 
a  dairyman  who  washed  the  cans.  In  Belleville,  111.,  typhoid  fever  was 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


477 


disseminated  in  the  milk  of  a  dairyman  whose  wife  was  a  carrier  for  7 
months  before  the  cases  became  sufficiently  numerous  to  direct  suspicion 
to  the  milk  route.  Lack  of  official  supervision  makes  the  occurrence  of 
such  cases  more  likely. 

Conn,  in  a  preliminary  report  on  the  milk  supplies  of  small  cities  in 
Connecticut  having  1  to  20  dealers,  found  that  preservatives  were  rarely 
used,  that  the  butterfat  was  often  below  legal  standard  but  this  he 
attributed  to  careless  mixing  of  the  milk  rather  than  to  skimming,  and 
watering  was  uncommon.  Bacterial  counts  ran  from  100  per  cubic 
centimeter  to  12,000,000  per  cubic  centimeter;  42  per  cent,  were  above 
50,000  and  23  per  cent,  were  above  1,000,000  per  cubic  centimeter. 
In  summer  few  counts  were  under  500,000  per  cubic  centimeter  which 
he  believed  was  due  to  insufficient  icing.  He  continued  the  work  and 
through  the  cooperation  of  the  State  Board  of  Health,  county  health 
officers  and  local  health  officers  was  able  to  arouse  interest  in  the  small 
cities.  The  samples  examined  increased  to  300  per  month  and  covered 
practically  all  of  the  towns  and  cities  large  enough  to  have  milk  routes. 
He  believed  that  he  demonstrated  the  feasibility  and  usefulness  of  a 
central  laboratory  in  cooperating  with  small  places  in  controlling  these 
milk  supplies.  As  a  result  of  his  work,  in  2  years  25  milk  inspectors  were 
appointed.  Previously  there  had  been  but  two  in  the  State.  In  towns 
where  inspectors  were  appointed  the  supplies  improved,  but  in  others 
little  progress  was  made. 

As  an  illustration  from  the  South  of  conditions  that  may  obtain  in  a 
small  city  the  experience  of  Jackson,  Miss.,  where  the  situation  was 
taken  in  hand  by  the  State  Board  of  Health,  may  be  cited.  One  hundred 
and  forty  milk  analyses  were  made.  Before  inspection,  the  scores  on 
the  " official"  score  card  varied  between  11  and  69  and  the  few  bacterial 
counts  ranged  from  50,000  to  200,000,000  and  averaged  22,000,000  per 
cubic  centimeter;  3  months  later  in  August,  1911,  the  counts  ranged  from 
88,000  to  5,800,000  and  averaged  1,200,000  per  cubic  centimeter.  The 
following  was  the  range  of  butterfat  in  the  milk  of  the  different  dairies 
before  and  after  inspection  was  begun: 


Dairy  No  

1 

2 

3 

4 

5 

6 

7 

Average 

Before  . 

2  8 

4  1 

2  9 

2  8 

3  6 

2  6 

0  8 

2  8 

After  

5.0 

6.4 

6  1 

5.0 

6  3 

6  0 

5  8 

Apparently  but  two  dairies  were  selling  unskimmed  milk  prior  to 
the  appointment  of  a  permanent  city  dairy  inspector,  but  under  the  guid- 
ance of  one,  the  dairymen  willingly  improved  their  premises  and  after  a 
little  instruction  adopted  approved  dairy  methods. 

Hastings  in  1910  made  the  statement  that  the  efforts  of  boards  of 
health  to  improve  milk  supplies  and  the  concentration  of  the  milk  busi- 


478  CITY  MILK  SUPPLY 

ness  in  the  hands  of  large  dealers  who  are  better  able  than  small  ones  to 
carry  out  the  regulations  and  introduce  improvements,  was  producing 
good  milk  in  many  cities  but  that  in  many  of  the  smaller  cities  of  Wiscon- 
sin it  was  almost  impossible  to  get  good  milk. 

Trueman  in  1905  and  1906  investigated  the  milk  supply  of  Chicago 
and  of  26  cities  of  Illinois  that  had  populations  of  from  10,000  to  60,000. 
He  reached  the  conclusion  that  the  chances  of  getting  good  milk  were 
better  in  Chicago  than  in  the  other  cities,  which  he  attributed  to  the 
lack  of  inspection  in  the  smaller  places.  In  a  long  table  of  butterfat 
tests  of  milk  collected  in  the  26  cities,  are  191  analyses  of  milk  that  was 
not  doctored  with  formaldehyde.  The  average  butterfat  test  of  these 
191  samples  was  3.53  per  cent,  and  the  average  total  solids  was  11.57  per 
cent.  Of  the  samples  37,  or  19.3  per  cent.,  were  below  the  legal  standard 
of  3  per  cent,  for  butterfat  and  120,  or  62.8  per  cent.,  were  below  the  legal 
standard  of  12  per  cent,  for  total  solids.  Had  not  the  standard  for  but- 
terfat been  so  very  low  the  butterfat  test  would  have  shown  more 
illegal  samples.  Out  of  210  samples  tested  for  butterfat,  total  solids 
and  formaldehyde  19,  or  9  per  cent.,  showed  the  preservative.  In 
156  of  the  samples  in  which  butterfat  and  total  solids  were  determined 
the  amount  of  sediment -was  estimated.  One  hundred  and  thirty-five, 
or  86.5  per.  cent.,  carried  visible  dirt;  in  33,  or  21  per  cent.,  the  amount 
was  large  enough  to  be  objectionable  to  consumers  who  are  used  to  dirty 
milk  and  in  45  per  cent,  to  those  who  would  object  to  plainly  visible 
dirt  on  the  bottom  of  the  bottle. 

Trueman  brings  out  the  fact  that  in  the  small  towns  many  of  the 
health  commissioners  absolutely  refused  to  move  in  the  matter  of  milk 
inspection  because  they  did  not  wish  to  incur  the  enmity  of  the  milk 
dealers.  The  ignorance  of  a  certain  class  of  health  officers,  in  this  case 
the  man  was  a  physician,  is  illustrated  by  the  letter  of  one  who  wrote 
to  know  what  preservatives,  if  any,  could  be  used  without  being  harmful 
in  the  milk  and  without  violating  the  law. 

In  1913  the  author  investigated  the  milk  supply  of  the  twin  cities 
of  Urbana  and  Champaign,  111.  These  two  cities  formed  practically 
one  community  of  22,500  inhabitants.  Urbana  paid  its  health  officer 
$100  a  year  and  Champaign  $180  which  means  that  the  offices  were 
perfunctorily  administered.  The  cities  had  identical  milk  codes  of  the 
modern  sort  but  no  attempt  was  made  to  enforce  them.  Table  124 
shows  that  in  1911,  20  of  the  dairies  that  supplied  the  cities  had  an  aver- 
age score  of  11.9  for  equipment  and  13.1  for  methods  with  a  total  average 
score  of  25.5  on  the  " official"  score  card.  These  scores  fairly  repre- 
sented the  state  of  the  average  dairy  farm  supplying  the  cities. 

The  late  G.  M.  Whitaker  held  that  milk  from  dairies  scoring  less  than 
40  should  not  be  a  marketable  commodity.  There  was  no  evidence  that 
skimming  and  watering  were  practised  and  preservatives  were  not  used, 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY 


479 


TABLE  124. — AVERAGE  SCORES  OP  20  DAIRIES1  IN  URBANA  AND  CHAMPAIGN,  ILL., 

1909,  1910  AND  1911 


Scorer 

Date 

Equipment 

Methods 

Total  score 

C  H  Yates                        

1909 

12.58 

15.79 

28.37 

C  H.  Yates   

1910 

13.50 

18.08 

31.58 

H  E  McNatt          

1911 

11.90 

13.10 

25.50 

1  It  does  not  appear  that  the  same  dairies  were  scored  at  the  different  scorings 
but  in  all  probability  many  of  them  were  the  same. 

but  the  milk  was  dirty  and  had  a  high  bacterial  count.  The  tests  of  the 
milk  of  19  dairies  supplying  dealer  A  and  of  that  of  21  dairies  supplying 
dealer  B  made  on  2  different  days  in  the  middle  of  October  may  be  taken 
as  illustrations  of  the  quality  of  milk  sold.  The  milks  of  the  dairies  sup- 
plying dealer  A  had  an  average  fat  test  of  4.3  per  cent,  with  tests  ranging 
from  3.2  to  5  per  cent,  of  butterfat,  while  the  acidity,  expressed  as  per- 
centage of  lactic  acid,  averaged  0.188  per  cent,  and  varied  from  0.166 
to  0.216  per  cent.  The  milks  of  the  dairies  supplying  dealer  B  had  an 
average  fat  test  of  3.8  per  cent,  with  tests  ranging  from  2.7  to  6.2  per  cent, 
while  the  acidity  averaged  0.199  per  cent,  and  varied  from  0.159  to  0.234 
per  cent.  The  milk  of  four,  or  21  per  cent.,  of  the  dairies  supplying  dealer 
A  had  a  bacterial  count  of  less  than  200,000  per  cubic  centimeter  and 
would  fall  in  grade  A;  that  of  13,  or  68  per  cent.,  of  his  dairies  had  a  count 
of  between  200,000  and  1,000,000  and  would  fall  in  grade  B  and  that  of 
2,  or  11  per  cent.,  would  fall  in  grade  C.  Of  dealer  B's  dairies  two,  or 
9  per  cent.,  would  be  classed  as  grade  A,  six,  or  29  per  cent.,  as  grade  B 
and  13,  or  62  per  cent.,  as  grade  C.  It  thus  appears  that  according  to 
the  New  York  grading  not  over  10  per  cent,  of  this  milk  was  fit  for  con- 
sumption raw  while  over  10  per  cent,  of  dealer  A's  milk  and  over  60  per 
cent,  of  dealer  B's  milk  was  fit  only  for  industrial  use.  The  high  counts 
are  partially  explainable  by  the  dirty  condition  of  the  milk  but  the  fact 
that  the  morning  milk  was  not  cooled  and  was  hauled  in  that  condition 
for  an  hour  or  two  over  hot  roads  to  the  dealer's  bottling  plants  was 
largely  responsible  for  the  high  counts  and  acidity. 

It  is  not  intended  to  convey  the  impression  that  the  milk  of  all  small 
towns  is  bad  and  to  deter  people  from  using  it.  Undoubtedly  some  small 
cities  have  good  milk  supplies  but  many  do  not  and  the  difficulties  in  the 
way  of  helping  them  to  better  ones  are  very  great.  At  first  thought  it 
might  seem  that  the  State  boards  of  health  might  be  of  assistance  but 
it  is  doubtful  if  they  can  be.  Very  few  have  nearly  enough  men  to  carry 
on  their  milk  work  properly.  The  consequence  is  that  their  usual  mode 
of  operation  is  to  have  their  inspectors  drop  down  on  a  town  where  they 
hastily  score  the  dairies  and  collect  milk  samples  from  the  delivery  wagons. 
Those  dealers  whose  milk  is  below  grade  are  prosecuted.  This  sort  of 


480  CITY  MILK  SUPPLY 

thing  is  not  going  to  help  very  much.  What  is  needed  is  the  patient 
sympathic  education  of  consumers  and  dealers,  and  for  this  work  there 
seem  to  be  neither  funds  nor  officials. 

In  contrast  to  the  small  communities  the  large  cities  are  served  by 
milk  companies  with  ample  capital  and  with  highly  trained  men.  The 
city  boards  of  health  have  well-equipped  laboratories  and  inspectors 
enough  to  cover  the  dairies  fairly  well.  The  consequence  is  that  where 
politics  does  not  blight  the  efforts  of  those  who  want  good  milk  supplies, 
something  akin  to  them  is  obtained.  The  chief  inspector's  staff  commonly 
consists  of  dairy  inspectors  who  devote  their  time  to  producing  dairies, 
milk  plant  inspectors,  who  look  after  the  various  types  of  plants  where 
milk  is  prepared  for  the  market  and  city  inspectors  who  attend  to  the 
shops  and  restaurants  where  milk  is  sold,  to  the  delivery  wagons,  to  the 
collection  of  milk  samples,  and  to  complaints  made  by  consumers.  In 
some  cities  where  the  bureau  of  food  control  is  organized  independently 
of  the  milk  inspection  bureau  the  former  undertakes  the  inspection  of 
stores  where  milk  is  sold.  The  cost  of  milk  inspection  varies  a  great 
deal  according  to  various  factors,  among  which  may  be  mentioned  the 
distance  of  producing  dairies  from  the  city  and  from  each  other,  the  loca- 
tion of  milk  plants  and  their  number,  the  amount  of  laboratory  work  and 
the  salaries  paid.  The  expenditures  for  milk  inspection  are  never  lavish. 
Generally  the  legislative  branch  of  the  government  which  votes  the  funds 
provides  inadequately  for  the  work  so  that  those  in  charge  have  to 
economize  severely.  In  some  places  no  attempt  is  made  to  inspect 
dairies  that  are  far  from  the  city  and  in  many  others  an  inspection  once 
or  twice  a  year  is  all  that  can  be  made. 

Cream. — The  quantity  of  cream  used  by  the  American  people  is 
steadily  increasing ;  in  fact,  in  some  markets  it  is  the  price  of  cream  that 
sets  that  of  milk.  Rich  creams,  those  of  35  per  cent,  and  more,  keep 
well  so  that  they  are  more  easily  shipped  long  distances  than  is  whole 
milk.  This  often  results  in  the  cream  supply  of  a  city  being  derived  from 
sources  entirely  distinct  from  the  milk  supply;  a  dairyman  may  produce 
all  of  the  milk  he  sells  but  purchase  all  of  the  cream  he  markets  from  a 
creamery  300  miles  away.  Cream  ought  to  be  produced  and  handled 
in  the  same  careful  way  that  milk  is  and  in  particular  the  separators 
should  be  kept  scrupulously  clean  but  sanitary  supervision  of  the  cream 
supply  is  frequently  neglected.  Apparently  there  is  no  other  reason  for 
this  than  that  cream  is  used  less  generally  than  milk  and  so  there  is 
somewhat  less  likelihood  of  people  becoming  infected  from  it  than  from 
milk.  Nevertheless,  the  danger  exists  for  epidemics  like  that,  for  instance, 
of  septic  sore  throat  in  Concord,  N.  H.,  have  been  traced  to  cream.  More- 
over, the  fact  that  in  extremely  hot  spells  and  at  other  times,  also,  a 
temporary  heavy  demand  forces  dealers  to  get  cream  from  unusual 
sources,  makes  it  very  necessary  that  the  quality  of  the  cream  supply 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  481 

be  protected.  Boards  of  health  should  not  only  look  after  conditions 
that  attend  the  production  and  shipment  of  cream  but  they  should  make 
sure  that  it  is  properly  handled  at  soda  fountains,  restaurants,  hotels, 
candy  factories,  ice  cream  factories  and  other  places  where  it  is  used. 
Care  should  be  exercised  also  to  see  that  cream  is  properly  branded  as 
to  its  fat  content  and  that  it  is  not  adulterated  by  the  substitution  of 
other  fats  for  butterfat.  Good  cream  and  the  products  made  from  it  are 
healthful  and  their  increased  use  by  the  public  is  wholly  commendable; 
every  effort  should  be  made  to  insure  their  continued  purity  and  safety. 

Daily  Consumption  of  Milk  in  the  Larger  Cities  of  the  U.  S. — The 
magnitude  of  the  task  of  controlling  the  milk  supplies  of  our  large  cities 
ma'y  be  appreciated  from  the  consideration  of  a  few  facts  relative  to  the 
production  and  distribution  of  milk  in  some  of  them. 

In  Boston  the  milk  comes  from  all  of  the  New  England  States  except 
Rhode  Island,  from  New  York  and  from  Canada.  It  is  produced  on 
about  6,700  farms  the  furthest  distant  of  which  is  270  miles  away. 
In  1914,  the  daily  consumption  of  milk  was  308,880  qt.  which  were  dis- 
tributed by  205  wagon  dealers  and  in  4,099  shops.  In  1911,  215  wagon 
dealers  used  666  wagons  in  delivering  the  milk.  Of  these  134  firms  used 
one  wagon,  48,  two  wagons,  11,  three  wagons  and  6,  four  wagons. 
One  dealer  used  25,  one  50  and  one  100  wagons.  In  1914  there  were  con- 
sumed in  the  city  1,163,620  gal.  of  40  per  cent,  cream  of  which  373,030 
gal.  were  sold  to  householders  and  790,590  gal.  were  sold  for  manufacture. 
There  were  also  used  1,874,275  gal.  of  15  per  cent,  cream  of  which 
4,159,270  gal.  went  to  manufacturers.  Five  thousand,  one  hundred 
and  thirty-six  dairy  inspections  and  2,246  milk  plant  inspections  were 
made;  21,984  samples  were  examined. 

New  York  City  in  1912  drew  its  daily  milk  supply  of  2,500,000  qt. 
from  44,000  farms  located  in  New  York,  New  Jersey,  Pennsylvania, 
Connecticut,  Vermont,  and  Massachusetts.  Cream  was  received  also 
from  Ohio  and  Canada.  The  "milk  shed"  covered  an  area  of  about 
50,000  sq.  miles.  The  milk  was  produced  by  350,000  cows  and  was 
shipped  from  1,100  creameries  over  11  different  railroads,  the  shortest 
haul  being  50  miles  and  the  longest  425.  It  was  received  in  New  Yoi*k 
at  15  different  terminals,  delivered  in  5,500  wagons  and  dispensed  at 
14,000  stores.  It  was  estimated  that  127,000  persons  handled  the  milk 
daily.  There  were  56  milk  inspectors  of  whom  one-half  were  assigned  to 
country  duty  and  one-half  to  city. 

In  Chicago  in  1910  the  milk  was  derived  from  17  counties  of  the  States 
of  Wisconsin,  Indiana  and  Illinois.  The  daily  supply  amounted  to 
1,000,000  qt.  and  was  produced  by  120,000  cows  on  12,000  dairy  farms. 
At  that  time  75  per  cent,  of  the  milk  was  pasteurized  and  two-thirds  of 
that  sold  at  retail  was  bottled  in  the  country. 

The  daily  consumption  of  milk  in  Detroit  in  1914  was  260,000  qt.,  of 

31 


482  CITY  MILK  SUPPLY 

which  7  per  cent,  was  produced  within  10  miles  of  the  city,  38.8  per  cent, 
within  10  to  20  miles,  and  28.8  per  cent,  within  20  to  30  miles.  One  per 
cent,  of  the  milk  was  sold  at  the  stores.  At  the  present  time  all  milk 
except  certified  and  class  A  milk  is  pasteurized  in  66  milk  plants  of  which 
56  use  the  vat  system  and  10  the  continuous.  Philadelphia  consumes 
540,000  qt.  of  milk  daily,  Baltimore  137,000,  St.  Louis  125,000  and  New 
Orleans  80,000. 

Annual  Reports. — The  annual  reports  of  the  milk  inspection  bureaus 
broadly  speaking  are  of  two  types.  One  is  little  more  than  a  statement 
to  the  tax-payers  of  the  cost  of  conducting  the  work.  The  number  of 
employees  and  the  total  amounts  of  their  salaries  are  given,  and  also 
the  number  of  inspections,  chemical  and  bacteriological  analyses,  a  sum- 
mary of  their  results,  etc.,  appears  in  tabular  form.  Frequently  such 
reports  form  part  of  a  town  report  or  of  some  municipal  officer  and  are 
tucked  away  inconspicuously  therein.  They  are  of  little  value  to  the 
ordinary  man.  The  other  type  appeals  to  milk  consumers  in  general 
and  aims  to  advance  the  interests  of  producers,  retailers  and  the  public. 
Such  reports  are  published  separately;  they  should  always  contain  a  plain 
statement  of  the  location  of  the  milk-producing  area  and  of  how  the  milk 
is  brought  to  the  city.  Where  there  are  several  milk-producing  districts 
the  source  of  each  dealer's  supply  should  be  indicated.  It  would  seem 
almost  unnecessary  to  mention  this  but  one  may  peruse  report  after  report 
and  not  find  a  hint  as  to  where  the  milk  comes  from.  It  should  be  told 
how  much  milk  of  different  classes  is  used,  as,  for  instance,  of  the  certified, 
the  inspected  and  the  ordinary  milk.  The  requirements  for  pasteurized 
milk,  the  mode  of  enforcing  them  and  the  amount  of  such  milk  used 
should  be  stated.  If  the  milk  is  graded,  the  grades  should  be  defined 
and  the  quantities  of  each  used  should  be  made  known.  In  the  smaller 
cities  a  brief  description  of  each  dealer's  supply  can  be  given.  An  en- 
deavor should  be  made  to  present  analytical  results  in  such  form  that 
they  will  be  intelligible  to  people  who  use  the  milk.  The  writer  firmly 
believes  that  the  dealers  should  be  rated  on  the  basis  of  the  quality  of  the 
milk  sold  during  the  year  and  that  in  making  up  this  rating  the  dairy 
scores,  the  butterfat,  content  of  the  milk  and  the  bacterial  counts,  should 
all  be  taken  into  account.  The  reports  may  well  treat  of  some  feature 
of  milk  supply  such  as  the  necessity  of  keeping  milk  cool,  the  abuse  of 
milk  bottles,  the  value  of  milk  as  a  food  or  the  like.  Any  particular  defect 
of  the  supply  may  be  discussed  with  the  public  or  some  commendable 
feature  may  be  dwelt  on.  Often  an  account  of  what  inspectors  are  doing 
tends  to  lead  the  public  to  appreciate  their  services. 

The  Public  Milk  Supply. — In  conclusion,  it  may  be  said  that  an 
impure  raw  milk  supply  is  a  source  of  disease  and  death  to  the  com- 
munity that  uses  it.  Its  victims  are  chiefly  the  women  and  children 
because  they  partake  of  milk  most  freely.  Such  milk  is  not  the  cause 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  483 

of  all  cases  of  disease  that  may  be  milk-borne  for  these  diseases  are 
transmitted  in  other  ways,  but  communities  that  neglect  to  protect 
their  milk  supplies  are  likely  to  and  probably  nearly  always  do  suffer 
an  excess  of  these  sicknesses.  The  milk  business  itself  does  not  thrive, 
for  the  milk  is  regarded  with  suspicion  and  is  not  of  the  character  to 
appeal  to  the  housewife. 

The  milk  supply  of  the  future  will  probably  be  graded  because  failure 
to  do  so  makes  mediocrity  the  standard;  those  who  are  able  and  willing 
to  produce  superior  milk  cannot  afford  to  compete  with  those  who  will  not. 
The  establishment  of  grades  gives  every  dairyman  the  opportunity  to 
produce  the  kind  of  milk  he  wants  and  to  sell  it  at  the  price  it  merits. 
A  regulated  supply  furnishes  the  conditions  under  which  the  dairy 
business  prospers  most,  for  it  eliminates  unfair  competition  and  estab- 
lishes public  confidence  in  the  product.  An  abundant  supply  of  in- 
spected, pasteurized  milk  is  one  of  the  greatest  blessings  a  community  can 
have  for  it  affords  cheap  wholesome  food  of  such  excellence  that  it  finds  its 
way  into  every  home. 

SOURCES 

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HAGGARD,  "Rural  Denmark  and  Its  Lessons,"  1913. 

"Government's  Milk  Policy,"  Office  of  Information,  U.  S.  Dept.  Ag.,  July  27,  1913. 
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Association  of  Dairy  and  Milk  Inspectors,  p.  113,  1915. 
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January,  1916. 
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from  Milk-borne  Diseases,"  3d  Annual  Report  of  the  International  Association 

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163,  1912-14. 
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Milk  Supply,"  Bull.  337,  N.  Y.  Ag.  Expt.  Sta.,  April,  1911. 
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Oct.,  1913. 


484  CITY  MILK  SUPPLY 

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Jour.  Public  Health,  vol.  2,  No.  2,  pp.  105-106,  February,  1912. 
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Sta.,  July,  1912. 
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Public  Health,  vol.  6,  No.  7,  1916. 
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Farmer's  Bull.  413,  U.  S.  Dept.  Ag.,  August,  1910. 
STOKES  and  WEGEFARTH,  "The  Microscopic  Examination  of  Milk,"  Med.  Neivs,  vol. 

71,  pp.  45-48,  1897.- 
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Supplement  vol.  2,  pp.  214-222,  1906. 
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19,  No.  1,  March,  1906. 
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Ag.  Expt.  Sta.,  1905. 
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in  Milk,"  Am.  Jour.  Public  Hygiene,  vol.  18,  pp.  285-291,  1908. 
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Direct  Method,"  Jour.  Infect.  Diseases,  vol.  7,  pp.  632-640    1911. 
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of  the  City  of  Boston,  1905. 

SCANNELL,  "Some  Practical  Considerations  on  the  Presence  of  Leukocytes  and  Strep- 
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Method."     Am.  Jour,  of  Public  Health. 
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March,  1914. 
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Mar.  6,  1915. 
PEASE,  "The  Sanitary  Significance  of  Bacteria  in  Milk,"  Proc.  6th  Annual  Convention 

of  the  International  Milk  Dealer's  Association,  pp.  105-119,  October,  1913. 
BREW,  "A  Comparison  of  the  Microscopical  Method  and  the  Plate  Method  of  Count- 
ing Bacteria  in  Milk,"  Butt.  373,  N.  Y.  Ag.  Expt.  Sta.,  February,  1914. 
FROST,  "A  Rapid  Method  of  Counting  Living  Bacteria  in  Milk  and  Other  Richly 

Seeded  Materials,"  Jour.  A.  M.  A.,  vol.  66,  No.  12,  Mar.  18,  1916. 
"Bacteriological  Standards  for  Milk,"  U.  S.  Public  Health  Service,  Reprint  192  from 

the  Public  Health  Reports,  May,  1914. 
SEDGWICK  and  BATCHELDER,  "A  Bacteriological  Examination  of  the  Boston  Milk 

Supply,"  Boston  Med.  and  Surg.  Jour.,  vol.  126,  p.  25,  1892. 
CONN,  "Standards  for  Determining  the  Purity  of  Milk,"  Reprint  225  from  the  Public 

Health  Reports,  August,  1915,  U.  S.  Public  Health  Service. 

HASTINGS,  "The  Value  of  Chemical  and  Bacteriological  Examinations  in  Milk  Con- 
trol," 1st  Annual  Report  of  the  International  Association  of  Dairy  and  Milk 

Inspectors,  pp.  69-73,  1912. 
SAVAGE,  "Milk  and  the  Public  Health,"  1912. 
PRESCOTT,  "The  Source  and  Significance  of  B.  Coli  in  Milk,"    Proc.  6th  Annual 

Convention  of  the  International  Milk  Dealer's  Association,  pp.  36-43,  October, 

1913. 
KINYOUN  and  DIETER,  "On  the  Preparation  of  Endo's  Medium,"  Am.  Jour.  Public 

Health,  vol.  2,  No.  12,  pp.  979-980,  December,  1912. 


CONTROL  OF  THE  PUBLIC  MILK  SUPPLY  485 

KINYOUN  and  DIETER,  "  A  Bacteriological  Study  of  the  Milk  Supply  of  Washing- 
ton, D.  C.,"  Am.  Jour.  Public  Health,  vol.  2,  No.  4,  pp.  262-274,  April,  1912. 

KINYOUN,  "A  Bacteriological  Index  for  Dirt  in  Milk,"  2nd  Annual  Report  of  the 
International  Association  of  Dairy  and  Milk  Inspectors,  pp.  139-149,  1913. 

ROGERS  and  DAHLBERG,  "The  Origin  of  Some  of  the  Streptococci  Found  in  Milk," 
Jour.  Ag.  Res.,  vol.  1,  No.  6,  pp.  491-511,  March,  1914. 

ROGERS,  CLARK  and  EVANS,  "Colon  Bacteria  and  Streptococci  and  their  Significance 
in  Milk,"  Am.  Jour.  Public  Health,  vol.  6,  No.  4,  pp.  374-380,  1916. 

AYRES  and  JOHNSON,  "Ability  of  Streptococci  to  Survive  Pasteurization,"  Jour. 
Ag.  Res.,  vol.  2,  No.  4,  pp.  321-330,  1914. 

AYRES  and  JOHNSON,  "Ability  of  Colon  Bacilli  to  Survive  Pasteurization,"  Jour. 
Ag.  Res.,  vol.  3,  No.  5,  pp.  401-410,  1915. 

PARKER,  "Characteristics  of  Typhoid  Fever  Outbreaks,"  Proc.  4th  Meeting  of  the 
Illinois  Water  Supply  Association,  pp.  89-96,  1912. 

BOLDUAN,  "Typhoid  Fever  in  New  York  City,"  Monograph  Series  No.  3,  Dept. 
Health,  New  York  City,  1912. 

LEDERLE  and  RAYNOR,  "The  Milk  Supply  of  New  York  City,"  Monograph  Series 
No.  5,  Dept.  Health,  New  York  City,  1912. 

HENDERSON,  "What  Has  the  Dairy  Inspector  Done  and  What  Can  He  Do  to  Interest 
the  Farmer  in  the  Production  of  Clean  Milk,"  2nd  Annual  Report  of  the  Inter- 
national Dairy  and  Milk  Inspectors,  pp.  87-97,  1913. 

HENDERSON,  "Methods  Employed  and  Results  Obtained  in  Improving  the  Milk 
Supply  of  Seattle,"  1st  Annual  Report  of  the  International  Association  of  Dairy 
and  Milk  Inspectors,  pp.  17-29,  1912. 

WOODWARD,  "A  New  Method  of  Grading  Milk  and  Cream,"  Reprint  117  from  the 
Public  Health  Reports,  U.  S.  Public  Health  Service. 

THOMAS,  "A  Review  of  Practical  Methods  for  Supervising  the  Milk  Supply  of  Cities," 
Jour.  Am.  Public  Health  Assn.,  vol.  1,  No.  11,  pp.  798-807,  1911. 

PARK  and  HOLT,  "Report  Upon  the  Results  with  Different  Kinds  of  Pure  and 
Impure  Milk  in  Infant  Feeding  in  Tenement  Houses  and  Institutions  in  New 
York  City,"  Studies,  Rockefeller  Inst.  Med.  Res.,  vol.  2,  pp.  1-29,  1904. 

PARK  amd  WILLIAMS,  "Pathogenic  Microorganisms,"  1914. 

DAVIS,  "Prevention  of  Infant  Mortality  by  Breast  Feeding,"  Am.  Jour.  Public 
Health,  vol.  2,  No.  2,  pp.  67-71,  February,  1912. 

WILLIAMS,  "A  Study  of  Infant  Mortality  in  Rochester;  The  Relation  of  Market  Milk 
Thereto,"  N.  Y.  Med.  Jour.,  July  13,  1912. 

PRICE,  "Some  Statistics  Regarding  Infant  Mortality,"  3d  Annual  Report  of  the  In- 
ternational Association  of  Dairy  and  Milk  Inspectors,  pp.  95-104,  1914. 

PRICE,  "Vital  Statistics  for  1916,"  Bull,  of  the  Detroit  Board  of  Health,  vol.  6,  No.  7, 
1916. 

SCHERESCHEWSKY,  "Heat  and  Infant  Mortality,"  Reprint  155  from  the  Public  Health 
Reports,  Dec.  5,  1913,  U.  S.  Public  Health  Service,  1914. 

PL  ATT,  "Investigation  into  the  Relationship  of  Flies  and  Diarrheal  Disease  in  Chil- 
dren under  1  Year  of  Age  in  New  York  City,"  Am.  Jour.  Public  Health,  vol.  6,  No. 
2,  pp.  143-154,  February,  1916. 

LEVY,  "Discussion  of  Platt's  Investigation,"  Am.  Jour.  Public  Health,  vol.  6,  No.  2, 
pp.  154-155,  February,  1916. 

ROGERS,  "The  Storage  of  Milk  in  Thermophores,"  Farmers  Bull.  490,  U.  S.  Dept.  Ag. 

TONNEY  and  PILLINGER,  "The  Utility  of  the  Vacuum  Bottle  in  Infant  Feeding,"  Jour. 
A.  M.  A.,  vol.  58,  No.  20,  pp.  1495-1496,  May  18,  1912. 

DAVIS,  "Researches  into  the  Bacteriological  Contents  of  Milk  Prepared  and  Kept  in 
Thermos  Bottles  for  Infant  Feeding,"  Proc.  of  the  6th,  7th  and  8th  Annual  Con- 


486  CITY  MILK  SUPPLY 

ferences  of  the  American  Association  of  Medical  Milk  Commissions,  pp.  13-14, 

1912. 

McCLEARY,  "Infantile  Mortality  and  Infants'  Milk  Depots,"  1905. 
"Infant  Mortality  and  Milk  Stations,"  Special  Report  of  the  Committee  for  the 

Reduction  of  Infant  Mortality  of  the  New  York  Milk  Committee,  1912. 
HOPLIK,  "The  History  of  the  First  Milk  Depot  or  Goutte  deLait,  with  Consultation, 

in  America,"  Proc.  of  the  6th,  7th,  and  8th  Annual  Conferences  of  the  American 

Association  of  Medical  Milk  Commissions,  pp.  377-382,  1912-13-14. 
KERR,  "Certified  Milk  and  Infants'  Milk  Depots,"  Hygienic  Lab.  Bull.  56,  Public 

Health  and  Marine  Hospital  Service,  pp.  613-635,  1909. 
KERR,  "The  History,  Development  and  Statistics  of  Milk  Charities  in  the  United 

States,"  Reprint  50  from  Public  Health  Reports,  Public  Health  and  Marine  Hos- 
pital Service  of  the  United  States,  1910. 
KERR,  "Data  Regarding  Operations  of  Infants'  Milk  Depots  in  the  United  States 

in  1910,"  Proc.  5th  Annual  Conference  of  the  American  Association  of  Medical 

Milk  Commissions,  pp.  139-188,  1911. 
CONN,  "The  Character  of  Milk  in  Small  Communities,"  Proc.  3d  Annual  Session  of  the 

American  Medical  Milk  Commissions,  pp.  71-75,  1909. 
CONN,  "A  Scheme  for  Organization  and  Control  of  the  Milk  of  Small  Communities," 

Proc.  of  the  5th  Annual  Conference  of  the  American  Association  of  Medical  Milk 

Commissions,  pp.  109-116,  1911. 
"Dairy  Investigation  at  Jackson,  Miss.,"  Health  Bull,  Miss.  State  Board  of  Health, 

vol.  2,  No.  3,  pp.  14-15. 
HASTINGS,  "The  Production  of  a  Good  Supply  of  Milk  for  a  Small  City,"  Proc.  of  the 

4th  Annual  Session  of  Medical  Milk  Commissions,  pp.  66-75,  1910. 
TRUEMAN,  "Milk  Supply  of  Chicago  and  Twenty-six  Other  Cities,"  Bull.  120,  Univ. 

111.  Ag.  Expt.  Sta.,  1907. 
PARKER,  "The  Milk  Supply  of  the  Cities  of  Urbanaand  Champaign,  111.,"  2nd  Annual 

Report  of  the  International  Association  of  Dairy  and  Milk  Inspectors,  pp.  67-80, 

1913. 
41st,  42nd  and  43d  Annual  Reports  of  the  Health  Department  of  the  City  of  Boston, 

1912,  1913  and  1914. 
LEDERLE  and  RAYNOR,  "The  Milk  Supply  of  New  York  City,"  Monograph  Series 

No.  5,  Dept.  Health,  New  York  City,  September,  1912. 
Report  of  the  Department  of  Health  of  the  City  of  Chicago,  1907-1910. 
KREHL,  "Detroit's  Experience  in  Enforcing  Compulsory  Pasteurization  of  Its  Milk 

Supply,"  4th  Annual  Report  of  the  International  Dairy  and  Milk  Inspectors, 

p.  181,  1915. 


INDEX 


Abortion,  contagious,  60 

Aeration  of  milk,  156 

Age  of  milk  delivered  to  consumers,  224 

consumed  in  cities,  254 
Analyses,  publication  of,  453 
Animal  reports,  482 
Animals,  milk  of,  22 
Anthrax,  57 
Aspergillus,  278 

Auto  truck  for  hauling  milk,  198,  217 
Ayrshire  cattle,  101 

B 

Babies  milk  a  special,  282 
Bacillus  albolactus,  274 
butyricus,  273 
cereus,  274 
coli,  63,  67,  276,  448 
diphtherias,  69 
dysenteriae,  67 
enteriditis  sporogenes,  63 
lactimorbi,  59 
mesentericus,  273 
mucosus,  63 
paratyphosus,  67,  68 
subtilis,  20,  162,  163,  273,  274 
troilii,  275 
tuberculosis,  29,  162 

in  butter,  56 

in  cheese,  57 

in  ice  cream,  56 

in  oleomargarine,  56 
typhosus,  66,  67 

in  butter,  66 

in  buttermilk,  68 

in  ice  cream,  66 
vulgatus,  274 

Bacteria,  acid-forming,  447 
classes  of,  17 
count,  438,  440,  444 
decomposition  of  milk  by  harmless, 
19 


Bacteria,  effect  on  infants,  460 

increase  in  milk  in  hauling,  197,  198 
in  transportation  by  rail,  206 

in  milk,  16 

and  open  stable,  160 

putrefactive,  447 

tests  of  pasteurized  milk,  450 

in  the  udder,  145 
Bacterial  decomposition  of  milk,  stages  in, 

18 
Bacterium  abortus,  60,  148 

anthracis,  57 

welchii,  63,  273,  450,  471 
Bam  practices,  effect  on  milk  quality,  156, 
159 

alignment  of  cattle  in,  123 

alleys,  124 

basement,  116 

ceiling,  125 

combination,  120 

construction,  121 

double  stabling,  119 

dressing  room,  125 

floor,  122 
"gutters,  123 

lighting,  125 

loft,  116 

mangers,  124 

milk  room,  125 

office,  125 

planning,  121 

platforms,  123 

rectangular,  121 

round,  120,  121 

shed,  119 

stall  partitions,  123 

stanchions,  124 

types,  116 

walk,  124 
Bedding,  132 

contamination  of  milk  by,  163 
Bookkeeping,  357 
Boston  Milk  Inspector,  370 
Bottle  washing,  328 


487 


488 


INDEX 


Bottles,  323 

abuse,  327 

breakage,  326 

caps,  318,  323 

cases,  322 

disinfection,  331,  332 

filling,  316 

paper,  327 

pint,  cost  of  delivering,  345 

storage  and  inspection,  331 

thermos  type,  472 
Bottling  milk,  316 

hot,  292,  298 
Breeding  of  cow,  3 
Brown  Swiss  Cattle,  103 
Bull  associations,  113 

purebred,  113 

Butter  possible  infection  in  wrapping,  67 
Butterfat,  8 

influenced  by  cow,  14,  15 

by  feed,  11 


Cans,  333 

washing,  255 
Capping  bottles,  319 
Cars,  types  used  in  transporting  milk,  307 
Casein,  9 

recovery  of,  337 
Cattle  Ayrshire,  101 

breed,  choice  of,  112 

Brown  Swiss,  103 

Channel  Islands,  105 

dairy  type,  95 

domesticated,  origin  of,  94 

dual-purpose,  111 

French-Canadian,  109 

Guernsey,  105 

Holstein-Friesian,  99 

introduced  into  America,  94 

Jersey,  107 

native,  95 

sheltering,  115 

Shorthorn,  111 
Cells  in  milk,  7,  437 
Cellular  content  of  milk  determination  of, 

435 

Certified  dairies,   quantity  of  milk  pro- 
duced, 407 

milk,  percentage  of  city  supply,  407 

production  of,  403 

quality  of,  405 

rules  for  producing,  408-423 


Champaign,  111.,  milk  supply,  478 
Chemical  tests,  435 
Child  Welfare  stations,'  473 
Cholera  Asiatic,  68 
infantum,  471 
Clarification  of  milk,  256 
Clarifier  slime,  analysis  of,  258,  259 
Clean  milk,  defined,  375 

extra  cost  of  producing,  143,  189 
production,  essentials  of,  170 
Colostrum,  5 

Contamination,  air-borne,  161 
of  milk  by  bedding,  163 
by  bottling  machine,  166 
from  coat  of  the  cow,  150 
in  delivery,  340 
by  discharges  of  nose  and  mouth, 

149 

by  domestic  animals,  170 
by  feces,  149 
by  feeds,  162 
by  flies,  170 
by  humans,.  170 
by  ice,  169 
sources  of,  144 
by  straining,  153 
by  utensils,  163 
by  vermin,  170 
Contractor  milk,  229 

influence  on  dairy  districts,  231 
Control  of  the  milk  supply  in  Europe,  370 
measures  of  success  in,  459 
in  the  United  States,  370 
Cowpox,  58 

Cow,  breed,  choice  of,  112 
breeding  of,  3 

cleaning  by  hand  and  machine  com- 
pared, 159 

clipping  the  udder  of,  159 
maltreating,  11 
testing,  113 

associations,  114 
Cream,  239,  480 
separator,  239 
effect  on  bacteria  count,  154 


Dairies,  dirty,  181 

slop,  182 

Dairy  sanitation,  expensive,  143 
Dairying,  importance  of,  2 

different  branches  dominate  produc- 
ing territory,  230 


INDEX 


489 


Delivery  of  one  quart  of  milk  to  con- 
sumers, cost  of,  347 
of  milk  in  pint  and  quart  bottles 

compared,  347 
retail,  339 
in  Rochester,  New  York,  347,  348, 

349 

in  Washington,  D.  C.,  349 
outfit,  value  of  good  appearing,  34 
planning  the  route,  344 
wagon,  cost  of  operating,  225,  343 
load  carried,  345 
miles  traveled,  345 
Diarrhea,  61 

of  infants,  471 
Diphtheria,  61,  69 
Dirt  in  milk,  256 
Dirty  dairies,  181 

milk  at  U.  S.  Naval  Academy,  64 

danger  of,  20 

Disease  germs,  destroyed  by  pasteuriza- 
tion at  low  temperatures,  286 
discovery  of,  29 
effect  of  lactic  acid  on,  67 

of  pasteurization  on,  280 
thermal  death  points  of,  287 
Diseases,  communicable,  28 

mode  of  transmission,  76 
Disinfection  of  stables,  54 
Drip  pans,  254 


E 


Electric  cars  for  carrying  milk,  199 

Electricity,  sterilization  of  milk  by,  306 

Emulsors,  337 

Enzymes,  8,  280 

Epidemics  prevention  of,  450 


Flies,  132,  470 

breeding  in  dirt  floors,  134 

and  infant  mortality,  469 
Foot-and-mouth  disease,  57 
French-Canadian  cattle,  109 

G 

Gastro-enteritis,  due  to  fecal  contamina- 
tion, 62 

due  to  udder  infection,  61 
Goucher  process,  306 
Goutte  de  lait,  473 


Grading  of  milk,  21,  379,  454 
Guernsey  cattle,  105 

H 

Heat,  use  in  preserving  food,  263 
Heated  milk,  Frost  test  for,  437 
Heating  milk,  193 

unnatural,  271 
Hexose  sugar,  10 
Holders,  294 

continuous,  295 
Homogenized  milk,  335 
Hypochlorite,  332 


I 


Ice,  contamination  of  milk  by,  169 
Ice  houses,  139 

Infant  feeding,  pasteurized  milk  for,  280 
mortality,  459 

in  Boston,  Mass,  461 
class  mortality,  471 
in  Detroit,  Mich.,  467 
due  to  flies,  469 

to  heat,  470 

in  Rochester,  N.  Y.,  464 
Infection,  wrongfully   imputed    to    milk 

supply,  88 
Infectious  disease,  mode  of  transmissions, 

76 

Inspection  Bureau,  personnel  of,  424 
of  dairy  farms,  428 
of  delivery  system,  430 
of  milk  plants,  429 
of  milk  in  transit,  429 


Jackson,  Miss.,  milk  supply,  477 
Jersey  cattle,  107 


K 


Keffir,  225 

King  system  of  ventilation,  126 
Koplik,  pasteurization  of  milk  by,  265 
Kumiss,  25 


Laboratory  tests,  control  of  milk  supply 

by,  434 
Lactalbumin,  10 


490 


INDEX 


Lactation  period,  effect  on  milk,  14 

length  of,  3 
Lactglobulin,  10 

Lactic  acid,  effect  on  disease  germs,  67 
Lactometer,  6 

test,  435 
Lactose,  10 
Leukocytes,  436 
Litter,  132 

M 

Malta  fever,  59 
Manure,  care  of,  130 

carriers,  131 
Matzoon,  21 
Medical  inspection  of  employees,  251 

milk  commissions,  403 
Micrococcus  caseolyticus,  148 
luteus,  148 
melitensis,  59,  162 

Milk,  age  on  arrival  at  city  plant,  253 
of  handled  by  contractor,  215 
when  delivered  to  consumers,  224 
babies',  a  special,  282 
basis  on  which  purchased,  231 
beverages,  24,  337 
-borne  diseases,  30 
epidemics,  characteristics  of, 

86 
control  of,  90 

injury  done  by,  89 
prevention  of,  450 
bottling  of,  316 
business,  beginning  of,  1 

tendency  toward  concentration, 

234 

cars,  207 

cellular  content,  7 
certified,  403 

rules  for  producing,  408,-423 
changes  in  lactation  period,  14 
clarification  of,  256 
clean,  essentials  for  production  of, 

171 
code,  378 

dealers   and  producers  consulted 

in  framing,  455 
enforcement,  423 

proposed  by  New  York  Milk  Com- 
mittee, 385 
by  Whitaker,  382 
should  be  suited  to  community, 
381 


Milk,  color  of,  6 

composition  of,  4 

condensed,  25 

consumption  of,  in  large  cities,  481 

in  United  States,  2 
contests,  457 
control  by  contractor,  378 

by  federal  government,  376 

important  elements  in,  427 

by  laboratory  tests,  434 

measures  of  success,  459 

by  municipality,  378 

and  office  records,  427 

policies  should  be  defined, 
425 

principles  of,  374 

by  State,  377 

survey  of  producing  terri- 
tory, 426 
cooling,  155,  313 
cost  of  bottling,  318 

of  distributing  in  New  England, 

354 

in   Worcester    and    Springfield, 
Mass,  355 

of  hauling,  193 

of  production,  184, 

of  extra  quality c  143,  189 
decomposition   by  bateria,  18 
defined,  3 
depot  of  Koplik ,  265 

of  Straus,  266 
dirt  in,  256 
dirty,  20,  142 
effect  of  lactation  period  on,  14 

of  seasons  on,  15 
electric  conductivity    of,  7 
enzymes,  7,  280 
fat  globules  in,  7 
fecal  contamination  of,  149 
flow,  factors  influencing,  11 

variable,  11 
freezing  point  of,  7 
gases  in,  11 

grading  of,  21,  379,  454 
hauling  of,  193 
heated  test  for,  437 
hod,  151 

holding  at  low  temperature,  338 
in  the  home,  434 
homogenized,  335 
hours  on  the  delivery  wagon,  346 
houses,  135 


INDEX 


491 


Milk,  impossible  to  protect  from  infec- 
tion, 85,  285 
infected,  20 
infection  of,  by  ambulatory  cases,  85 

by  bottles  and  cans,  81 

by  carriers,  85 

by  cases  in  prodromal  stage,  85 

in  city  milk  plant,  81 

after  delivery,  84 

in  delivery,  83 

en  route  to  creamery  or  city,  80 

on  farm,  77 
inspection  and  sampling  begun  in  the 

United  States,  371 
inspectors,  424 
modified,  22 
opacity  of,  6 
pails,  small  top,  150 

sterilizing  and  protecting,  157 
plants,  235 

advantages  of,  242 

basement,  244 

classification  of,  244 

city,  cost  and  equipment,  247 
general  features,  242 

country,  235 

handling  milk  in,  238 

environment,  246 

general  plan,  246 

ground  floor  and  basement,  245 

inspection  of,  253 

minimum  requirements  for,  246 

more  than  one  story,  245 

plan  of,  246 

platforms,  253 

plumbing,  247 

score  card,  247 

shrinkage,  item  of,  334 

single  story,  245 

water  supply,  247 

wastes  of,  337 
powder,  25 
price  of  retail,  364 
problem,  advent  of,  228 
producers,  methods  of  paying,  235 
proteins,  9 
refractive  index,  7 
room,  125 

route,  cost  of  operating,  353 
sale  of,  in  stores,  431 
salts  in,  10 
sickness,  59 
specific  gravity  of,  6 


Milk,  standardizing,  261 
storage  in  tanks,  263 
supply,  482 
an  asset,  423 
of  cities,  476,  477,  480 
control  of,  by  contractor,  378 
by  federal  government,  376 
by  municipal  government,  378 
by  state  government,  377 
of  large  and  small  cities  contrasted, 

476 

public  482 

public  interest  in,  453 
tasting,  254 
uninspected  should  be  pasteurized, 

271 

valuable  food,  3 

variation  from  milking  to  milking,  12 
of  various  animals,  22 
a  vehicle  of  infection,  29 
water  in,  8 
Milking,  effect  of,  on  milk  flow,  11 

machines,  152 

Montclair,  N.  J.,  began  bacteria  exami- 
nations, 373 
Mosquitoes,  135 

Motor  vehicles  for  collecting  and  deliver- 
ing milk,  198,  217 

Mould  spores,  effect  of  pasteurization  on, 
277 

N 

North  score  card,  181 
system,  171,  238 

O 

Odors  in  milk,  156,  254 

Oidium  lactis,  19,  278 

Open  stable  and  germ  content  of  milk, 

160 
Oyster  milk  charity,  281 

P 

Painting,  effect  on  bacterial  count,  157 
Parasites  from  water,  130 
Paratyphoid  fever,  68 
Pasteurization,  ability  of  B.  coli  to  sur- 
vive, 276 
of  certain  groups  of  bacteria  to 

survive,  275 

of  mould  spores  to  survive,  277 
of  spore-bearing  organisms  to  sur- 
vive, 272 
of  streptococci  to  survive,  277 


492 


INDEX 


Pasteurization,  actual,  302 
an  additional  process,  282 
adopted  by  milk  contractors,  267 
applied  to  milk,  264 
arguments  for  and  against,  270 
bacteria  that  survive,  272,  275,  276, 

277 

and  bovine  infection  of  milk,  284 
in  bottle,  292,  297 
and  bottling  milk  hot,  298 
and  bovine  infection,  284 
changes  wrought  in  milk  by,  279 
checks  bacterial  changes  in  milk,  271 
and  child  welfare  stations,  281,  289 
by  consumer,  289 
cost  of,  310 
delays  souring,  271 
destruction  of  toxins  by,  278 
difficulties  encountered,  298 
and  dirty  dairying,  272 
effect  on  mould  spores,  277 
efficiency  of,  302 
future  of,  311 

holder  process  advent  of,  289 
and  human  infected  milk,  285 
and  importance  of  temperature  con- 
trol, 300 

at  low  temperatures,  286 
lowers  infant  morbidity  rate,  271 
of  milk  for  butter  making,  265 

for  cheese  making,  265 
prevents  spread  of  contagion,  270 
and  score  card,  284 
use  of,  in  the  United  States,  312 

Pasteurized  milk,  bacteria  tests  for,  450 
cooling  of,  303 
distributed  by  Straus,  266 
for  infant  feeding,  280 
introduced  by  Koplik,  265 
liable  to  recontamination,  283 
multiplication  of  bacteria  in,  278 
overconfidence  in,  283 
at  Randall's  Island,  N.  Y.,  266 
in  relation  to  scurvy,  281 

Pasteurizers,  regenerative,  295 

Pasteurizing  machines,  289 
milk  in  tanks,  291 
plants,  inspection  of,  304 

Paying  producers,  methods  of,  235 

Plastering,  effect  on  bacterial  count,  157 

Platforms,  123 

Pittsburgh,  improvement  in  milk  supply, 
214 


Preservatives,  435 

Producing    territory    dominated  by  dif- 
ferent types  of  dairying,  230 
Profits  in  the  milk  business,  551 
Proteins  in  milk,  9 
Purchase  of  milk,  231 

R 

Rabies,  58 

Rates  for  transporting  milk,  312 
Refrigeration  in  the  home,  339 
Retail  delivery  of  milk,  339 
Rutherford  system,  129 

S 

Scarlet  fever,  69 

Score  card  for  cream,  459 

dairy  cattle,  98 
farms,  173 

future  of,  179 

milk,  456 
plants,  247 

North,  180 

"official,"  175 

in  relation  to  bacteria,  177 

stores,  433 
Scurvy,  281 
Seal,  334 

Sediment  test,  434 
Septic  sore  throat,  69 

epidemics,  76 

Krumwiede  and  Valentine  on,  72 

Smillie  on,  75 

Smith  and  Brown  on,  71 
Shorthorn  cattle,  111 
Shrinkage  in  milk  plants,  334 
Skim-milk,  composition  of,  5 

a  source  of  tuberculosis,  37 
Slop  dairies,  182 
Sore  teats,  61 
Spirillum  choleras,  67,  68 
Spore-bearing  bacteria,  survive  pasteuri- 
zation, 272 
Spores,  mould  effect  of  pasteurization  on, 

277 

Stable,  open,  160 
Stables  disinfection  of,  54 
Stabling  cattle,  115 
Standardizing  milk,  261 
Steamboat,  use  in  transporting  milk,  199 
Steam,  economy  in  using,  339 

railroads,  transporting  milk  by,  200, 
203 


INDEX 


493 


Sterilization  of  milk  by  electricity,  306 

of  milk  by  ultra  violet  rays,  307 

of  pails,  157 

of  utensils,  164 
Storage  of  milk  in  tanks,  263 
Stores,  sale  of  milk  in,  431 
Straining  milk,  153 

Streptococci,  ability  to    withstand   pas- 
teurization, 277 

cause  of  gastro-enteritis,  61 

and  leukocytes,  436 

significance  of,  447 
Streptococcus  lacticus,  16,  71,  148,  149 

pyogenes,  71,  146 

Smith,  70,  72 
Surplus,  item  of,  236 
Swine,  tuberculosis  in,  55 


Tasting  milk,  254 

Temperature  of  milk  in  transit  by  rail, 

295 

handled  by  contractors,  215 
increase  in  hauling,  196 
Testing  milk,  254 
Toxins,    destruction    by    pasteurization, 

278 
Tuberculin,  39 

test   for   excluding    milk    from   the 

market,  41 
value  of,  44 

testing  in  Chester  Co.,  Pa.,  48 
in  Hawaii,  47 
lesson  of,  50 
in  Minnesota,  49 
in  Montclair,  New  Jersey,  49 
in  North  Carolina,  47 
in  Savannah,  Ga.,  48 
in  Wisconsin,  45 
Tuberculosis,  30 
aviran,  56 
control  by  Bang  method,  52 

in  the  United  States,  53 
Birmingham  method,  53 
by  immunization,  50 
Manchester  method,  51- 
Ostertag  method,  51 
tuberculin  testing,  51 
diagnosis  of,  37 

by  physical  examination,  38 
entrance  of  germs  into  the  body,  33 
frequency  of  infection  of  milk  with, 
34 


Tuberculosis,  germs  infect  milk  through 
the  feces,  34 

intradermal  test,  42 

length  of  life  of  bacilli  outside  the 
body,  36 

mode  of  infection  of  herd,  36 

nature  of,  32 

ophthalmic  test,  44 

passage  of  germs  from  the  body,  33 

slaughter-house  records,  56 

subcutaneous  test,  40 

in  swine,  55 
Typhoid  fever,  65 

in  Belleville,  111.,  476 

in  Berkeley,  Calif.,  286 

in  Camden,  N.  J.,  476 

in  North  Branch,  Minn.,  476 

-    U 

Udder,  bacteria  of,  145 

infection,  61 
Udders,  clipping,  159 

wiping,  150 

Ultra  violet  rays  for  sterilizing  milk,  307 
United  States  Naval  Academy,  unclean 

milk  at,  64 

Urbana,  111.,  milk  supply  of,  478 
Utensils,  contamination  of  milk  by,  163 

sterilization  of,  164 


Vacuum  cleaner,  159     • 

Ventilation,  126 

"Canadian  experiments,  128 
by  curtains,  130 
by  King  system,  126 
by  pierced  walls,  129 
by  Rutherford  system,  129 
by  windows,  126  v 

Vermin,  133 

W 

Washing  cans,  255 

powder  as  a  disinfectant,  331 
Wastes,  treatment  of  creamery,  337 
Water  supply  of  the  dairy  farms,  167 

of  the  milk  plant,  247 
Watering  cows,  130 
Whey,  composition  of,  5 
Whitewashing,  effect  on  bacteria  count, 

157 
Woman's  and  cow's  milk  compared,  23 


; 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
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WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
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FEE   161935     1 

KTORUBRARY  LC 

AN 

JUL281981 

lliJ'W    AC  /*Al  1C     rv 

UNiV.  Of  CALIF.,  B 

cRK. 

JAM  03  1995 

DEC  2,    1994 


LD  21-100m-8,'34 


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UNIVERSITY  OF  CALIFORNIA  LIBRARY 


